:root {
  color-scheme: dark;
  --bg: #0b1020;
  --bg-deep: #080c17;
  --surface: #11182c;
  --surface-raised: #161f38;
  --surface-soft: #0f1629;
  --line: rgba(145, 160, 196, 0.17);
  --line-strong: rgba(145, 160, 196, 0.31);
  --text: #f2f5ff;
  --muted: #9ba8c5;
  --muted-2: #687694;
  --blue: #6b8cff;
  --blue-bright: #8ca5ff;
  --cyan: #5be6da;
  --green: #76e2ae;
  --purple: #c09cff;
  --red: #ff8293;
  --yellow: #f7ce76;
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.3);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

html[data-theme="light"] {
  color-scheme: light;
  --bg: #f3f6fb;
  --bg-deep: #eaf0f8;
  --surface: #ffffff;
  --surface-raised: #f8faff;
  --surface-soft: #edf2fa;
  --line: rgba(41, 59, 91, 0.13);
  --line-strong: rgba(41, 59, 91, 0.24);
  --text: #17213b;
  --muted: #56647e;
  --muted-2: #77839c;
  --blue: #526fdb;
  --blue-bright: #3f61dc;
  --cyan: #0d9f9b;
  --green: #198d61;
  --purple: #8459c6;
  --red: #bd4b5f;
  --yellow: #a87112;
  --shadow: 0 24px 70px rgba(34, 55, 92, 0.12);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.55;
  transition: background 0.3s ease, color 0.3s ease;
}

button, select { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
a { color: inherit; text-decoration: none; }
button { cursor: pointer; }

.container { width: min(1160px, calc(100% - 48px)); margin: 0 auto; }
.section-pad { padding: 112px 0; }
.section-dark { background: var(--bg-deep); }

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 99;
  padding: 9px 14px;
  background: var(--blue);
  color: #fff;
  border-radius: 8px;
  transform: translateY(-180%);
  transition: transform .2s ease;
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s ease, box-shadow .25s ease;
}
.site-header.is-scrolled { border-color: var(--line); box-shadow: 0 10px 30px rgba(0, 0, 0, .12); }
.header-inner { min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 11px; min-width: 190px; }
.brand-mark { display: grid; width: 34px; height: 34px; place-items: center; border: 1px solid var(--blue); border-radius: 9px; color: var(--blue-bright); font-family: "SFMono-Regular", Consolas, monospace; font-size: 12px; font-weight: 700; box-shadow: 0 0 20px color-mix(in srgb, var(--blue) 21%, transparent); }
.brand strong { display: block; font-size: 14px; letter-spacing: .1em; }
.brand-dot { color: var(--cyan); }
.brand small { display: block; margin-top: 1px; color: var(--muted-2); font-size: 10px; letter-spacing: .08em; text-transform: uppercase; }
.main-nav { display: flex; align-items: center; gap: 30px; color: var(--muted); font-size: 13px; }
.main-nav a { position: relative; transition: color .2s ease; }
.main-nav a::after { position: absolute; right: 0; bottom: -8px; left: 0; height: 2px; border-radius: 4px; background: var(--cyan); content: ""; transform: scaleX(0); transition: transform .2s ease; }
.main-nav a:hover, .main-nav a.is-active { color: var(--text); }
.main-nav a.is-active::after { transform: scaleX(1); }
.icon-button { display: grid; width: 38px; height: 38px; place-items: center; border: 1px solid var(--line); border-radius: 10px; background: var(--surface-soft); color: var(--muted); transition: border-color .2s ease, color .2s ease, transform .2s ease; }
.icon-button:hover { border-color: var(--blue); color: var(--text); transform: translateY(-1px); }
.icon { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; stroke-width: 1.7; }
.icon-moon { display: none; }
html[data-theme="light"] .icon-sun { display: none; }
html[data-theme="light"] .icon-moon { display: block; }
.scroll-progress { height: 2px; background: transparent; }
.scroll-progress span { display: block; width: 0; height: 100%; background: linear-gradient(90deg, var(--blue), var(--cyan)); transition: width .08s linear; }

.hero { position: relative; overflow: hidden; padding-top: 96px; background: radial-gradient(circle at 78% 30%, color-mix(in srgb, var(--blue) 11%, transparent), transparent 30%), var(--bg); }
.hero::before { position: absolute; top: 8%; right: -12%; width: 600px; height: 600px; border: 1px solid color-mix(in srgb, var(--blue) 13%, transparent); border-radius: 50%; content: ""; box-shadow: 0 0 0 45px color-mix(in srgb, var(--blue) 3%, transparent), 0 0 0 110px color-mix(in srgb, var(--blue) 2%, transparent); pointer-events: none; }
.hero-grid { position: relative; display: grid; grid-template-columns: minmax(0, 1.04fr) minmax(400px, .96fr); align-items: center; gap: 72px; min-height: 500px; }
.eyebrow, .overline { margin: 0; color: var(--cyan); font-family: "SFMono-Regular", Consolas, monospace; font-size: 10px; font-weight: 700; letter-spacing: .17em; text-transform: uppercase; }
.status-dot { display: inline-block; width: 7px; height: 7px; margin-right: 8px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 5px color-mix(in srgb, var(--green) 12%, transparent); vertical-align: 1px; }
.hero h1 { max-width: 680px; margin: 22px 0 16px; font-size: clamp(42px, 5.5vw, 76px); font-weight: 740; letter-spacing: -.065em; line-height: 1.01; }
.text-gradient { color: var(--cyan); background: linear-gradient(100deg, var(--cyan), var(--blue-bright)); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.hero-lede { max-width: 580px; margin: 0; color: var(--blue-bright); font-size: 17px; font-weight: 650; letter-spacing: -.01em; }
.hero-description { max-width: 560px; margin: 17px 0 0; color: var(--muted); font-size: 16px; }
.hero-actions { display: flex; align-items: center; gap: 25px; margin-top: 32px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 13px; min-height: 45px; padding: 0 17px; border: 1px solid transparent; border-radius: 10px; font-size: 13px; font-weight: 700; transition: transform .2s ease, box-shadow .2s ease, background .2s ease, border-color .2s ease; }
.button:hover { transform: translateY(-2px); }
.button-primary { background: var(--blue); color: #fff; box-shadow: 0 11px 24px color-mix(in srgb, var(--blue) 25%, transparent); }
.button-primary:hover { background: var(--blue-bright); box-shadow: 0 15px 30px color-mix(in srgb, var(--blue) 34%, transparent); }
.button-secondary { border-color: color-mix(in srgb, var(--blue) 50%, var(--line)); background: color-mix(in srgb, var(--blue) 10%, var(--surface)); color: var(--blue-bright); }
.button-secondary:hover { border-color: var(--blue); background: color-mix(in srgb, var(--blue) 16%, var(--surface)); }
.text-link { color: var(--muted); font-size: 13px; font-weight: 600; transition: color .2s ease; }
.text-link:hover { color: var(--text); }
.text-link span { margin-left: 6px; color: var(--cyan); }

.hero-visual { position: relative; min-height: 355px; display: grid; place-items: center; }
.code-window { width: min(100%, 480px); overflow: hidden; border: 1px solid var(--line-strong); border-radius: 15px; background: color-mix(in srgb, var(--surface) 91%, transparent); box-shadow: var(--shadow), 0 0 60px color-mix(in srgb, var(--blue) 10%, transparent); transform: perspective(1000px) rotateY(-5deg) rotateX(2deg); }
.window-bar { display: flex; align-items: center; height: 42px; padding: 0 15px; border-bottom: 1px solid var(--line); background: var(--surface-raised); }
.window-bar > span { width: 7px; height: 7px; margin-right: 6px; border-radius: 50%; background: var(--muted-2); }
.window-bar > span:first-child { background: var(--red); }
.window-bar > span:nth-child(2) { background: var(--yellow); }
.window-bar > span:nth-child(3) { background: var(--green); }
.window-bar small { margin-left: 13px; color: var(--muted-2); font: 10px "SFMono-Regular", Consolas, monospace; }
.code-lines { padding: 27px 24px 30px; font: 12px/2.55 "SFMono-Regular", Consolas, monospace; }
.code-lines p { margin: 0; white-space: nowrap; }
.code-lines i { display: inline-block; width: 28px; color: var(--muted-2); font-style: normal; }
.code-lines span { color: var(--muted); }
.code-lines em { color: var(--cyan); font-style: normal; }
.code-lines strong { color: var(--green); }
.code-key { color: var(--purple); font-weight: 500; }
.cursor-line { color: var(--cyan) !important; animation: blink 1.05s steps(2, start) infinite; }
.floating-chip { position: absolute; display: inline-flex; align-items: center; gap: 8px; padding: 8px 12px; border: 1px solid var(--line-strong); border-radius: 9px; background: var(--surface-raised); box-shadow: 0 10px 28px rgba(0, 0, 0, .2); color: var(--muted); font: 10px "SFMono-Regular", Consolas, monospace; }
.floating-chip span { color: var(--cyan); }
.chip-context { top: 7%; left: -3%; animation: float 4.5s ease-in-out infinite; }
.chip-check { right: -2%; bottom: 6%; animation: float 4.5s 1.2s ease-in-out infinite; }

.rap-callout { position: relative; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 20px; margin-top: 53px; padding: 21px 26px; border: 1px solid color-mix(in srgb, var(--blue) 28%, var(--line)); border-radius: var(--radius-md); background: linear-gradient(100deg, color-mix(in srgb, var(--blue) 10%, var(--surface)), color-mix(in srgb, var(--cyan) 3%, var(--surface))); box-shadow: 0 12px 40px rgba(0, 0, 0, .09); }
.rap-label { align-self: stretch; display: grid; min-width: 68px; place-items: center; border-right: 1px solid var(--line); color: var(--blue-bright); font: 700 11px "SFMono-Regular", Consolas, monospace; letter-spacing: .08em; }
.rap-callout .overline { margin-bottom: 2px; color: var(--muted-2); font-size: 9px; }
.rap-text { margin: 0; font-size: 15px; font-weight: 600; }
.rap-meta { color: var(--muted); font: 10px "SFMono-Regular", Consolas, monospace; white-space: nowrap; }
.pulse-ring { display: inline-block; width: 6px; height: 6px; margin-right: 7px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 0 4px color-mix(in srgb, var(--cyan) 13%, transparent); }

.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 60px; margin-bottom: 54px; }
.section-heading h2, .challenge-heading h2 { max-width: 700px; margin: 16px 0 0; font-size: clamp(32px, 4vw, 49px); letter-spacing: -.052em; line-height: 1.05; }
.muted-text { color: var(--muted-2); }
.section-intro { max-width: 340px; margin: 0 0 4px; color: var(--muted); font-size: 14px; }
.analogy-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)) minmax(280px, .82fr); gap: 16px; }
.concept-card, .bridge-card { min-height: 420px; padding: 26px; border: 1px solid var(--line); border-radius: var(--radius-lg); background: var(--surface); }
.concept-card { position: relative; overflow: hidden; }
.concept-card::after { position: absolute; right: -100px; bottom: -150px; width: 280px; height: 280px; border-radius: 50%; content: ""; opacity: .11; filter: blur(2px); }
.functional-card::after { background: var(--green); }
.nonfunctional-card::after { background: var(--purple); }
.card-topline { display: flex; align-items: center; justify-content: space-between; }
.card-index { color: var(--muted-2); font: 11px "SFMono-Regular", Consolas, monospace; }
.pill { padding: 4px 8px; border-radius: 6px; font: 10px "SFMono-Regular", Consolas, monospace; }
.pill-green { background: color-mix(in srgb, var(--green) 11%, transparent); color: var(--green); }
.pill-purple { background: color-mix(in srgb, var(--purple) 11%, transparent); color: var(--purple); }
.concept-icon { display: grid; width: 59px; height: 59px; margin: 35px 0 23px; place-items: center; border: 1px solid var(--line); border-radius: 15px; background: var(--surface-raised); }
.concept-icon svg { width: 36px; height: 36px; fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; stroke-width: 1.5; }
.functional-card .concept-icon { color: var(--green); }
.nonfunctional-card .concept-icon { color: var(--purple); }
.concept-card h3, .bridge-card h3 { margin: 0; font-size: 21px; letter-spacing: -.025em; }
.analogy-title { margin: 5px 0 16px; color: var(--blue-bright); font-size: 13px; font-weight: 650; }
.concept-card > p:not(.analogy-title), .bridge-card > p { position: relative; z-index: 1; max-width: 300px; margin: 0; color: var(--muted); font-size: 13px; }
.concept-card strong { color: var(--text); }
.example-box { position: relative; z-index: 1; margin-top: 27px; padding: 13px 14px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface-soft); color: var(--muted); font-size: 12px; }
.example-label { display: block; margin-bottom: 4px; color: var(--muted-2); font: 9px "SFMono-Regular", Consolas, monospace; letter-spacing: .12em; text-transform: uppercase; }
.bridge-card { display: flex; flex-direction: column; justify-content: center; background: linear-gradient(140deg, color-mix(in srgb, var(--blue) 11%, var(--surface)), var(--surface)); }
.bridge-line { display: flex; align-items: center; gap: 8px; margin-bottom: 28px; color: var(--muted-2); font: 9px "SFMono-Regular", Consolas, monospace; text-transform: uppercase; }
.bridge-line .line { width: 31px; height: 1px; background: var(--cyan); }
.bridge-card > p { margin-top: 14px; }
.story-template { display: flex; flex-wrap: wrap; gap: 5px; align-items: center; margin-top: 23px; padding: 12px; border: 1px dashed color-mix(in srgb, var(--blue) 50%, var(--line)); border-radius: 9px; font: 11px "SFMono-Regular", Consolas, monospace; }
.story-template span { color: var(--muted); }
.story-template strong { color: var(--cyan); font-weight: 500; }
.bridge-note { margin-top: 23px !important; color: var(--muted-2) !important; font-size: 11px !important; }
.spark { margin-right: 5px; color: var(--yellow); }
.anatomy-section { margin-top: 82px; }
.mini-heading { display: flex; justify-content: space-between; align-items: center; margin-bottom: 19px; }
.line-label { color: var(--muted-2); font: 10px "SFMono-Regular", Consolas, monospace; }
.anatomy-grid { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.anatomy-item { display: flex; align-items: flex-start; gap: 15px; padding: 22px 22px 22px 0; }
.anatomy-item + .anatomy-item { padding-left: 22px; border-left: 1px solid var(--line); }
.anatomy-number { color: var(--blue-bright); font: 11px "SFMono-Regular", Consolas, monospace; }
.anatomy-item h4 { margin: 0; font-size: 14px; }
.anatomy-item p { margin: 4px 0 0; color: var(--muted); font-size: 12px; }

.laboratory-section { position: relative; overflow: hidden; background: var(--bg); }
.laboratory-section::before { position: absolute; top: 10%; left: -260px; width: 500px; height: 500px; border: 1px solid color-mix(in srgb, var(--cyan) 8%, transparent); border-radius: 50%; content: ""; }
.lab-heading { margin-bottom: 36px; }
.lab-status { padding: 8px 12px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--muted); font: 10px "SFMono-Regular", Consolas, monospace; }
.simulator-shell { position: relative; display: grid; grid-template-columns: .84fr 1.16fr; border: 1px solid var(--line-strong); border-radius: var(--radius-lg); background: var(--surface-soft); box-shadow: var(--shadow); }
.simulator-panel { padding: 30px; }
.story-panel { border-right: 1px solid var(--line); }
.panel-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; }
.panel-title-group { display: flex; align-items: center; gap: 12px; }
.panel-number { display: grid; width: 30px; height: 30px; place-items: center; border: 1px solid var(--blue); border-radius: 8px; color: var(--blue-bright); font: 11px "SFMono-Regular", Consolas, monospace; }
.panel-header .overline { margin-bottom: 2px; color: var(--muted-2); font-size: 9px; }
.panel-header h3 { margin: 0; font-size: 18px; letter-spacing: -.02em; }
.syntax-tag { padding: 5px 7px; border: 1px solid color-mix(in srgb, var(--purple) 35%, var(--line)); border-radius: 5px; color: var(--purple); font: 9px "SFMono-Regular", Consolas, monospace; letter-spacing: .08em; }
.syntax-green { border-color: color-mix(in srgb, var(--green) 35%, var(--line)); color: var(--green); }
.panel-description { min-height: 42px; margin: 22px 0 24px; color: var(--muted); font-size: 12px; }
.story-controls { display: grid; gap: 13px; }
.field-group { display: block; }
.field-group > span { display: block; margin-bottom: 6px; color: var(--text); font: 11px "SFMono-Regular", Consolas, monospace; }
.field-group small { color: var(--muted-2); font-size: 9px; }
select { width: 100%; min-height: 42px; padding: 0 34px 0 12px; border: 1px solid var(--line); border-radius: 8px; outline: none; background: var(--surface); color: var(--muted); font-size: 12px; appearance: none; background-image: linear-gradient(45deg, transparent 50%, var(--muted-2) 50%), linear-gradient(135deg, var(--muted-2) 50%, transparent 50%); background-position: calc(100% - 16px) 18px, calc(100% - 12px) 18px; background-size: 4px 4px, 4px 4px; background-repeat: no-repeat; transition: border-color .2s ease, box-shadow .2s ease; }
select:focus { border-color: var(--blue); box-shadow: 0 0 0 3px color-mix(in srgb, var(--blue) 16%, transparent); }
select.is-selected { color: var(--text); }
.story-output { margin-top: 22px; padding: 14px; border: 1px solid color-mix(in srgb, var(--blue) 32%, var(--line)); border-radius: 11px; background: color-mix(in srgb, var(--blue) 7%, var(--surface)); }
.output-label { display: flex; align-items: center; gap: 7px; color: var(--muted-2); font: 9px "SFMono-Regular", Consolas, monospace; letter-spacing: .05em; text-transform: uppercase; }
.output-dot { width: 5px; height: 5px; border-radius: 50%; background: var(--blue-bright); }
.copy-button { margin-left: auto; padding: 0; border: 0; background: transparent; color: var(--blue-bright); font: 9px "SFMono-Regular", Consolas, monospace; text-transform: uppercase; }
.copy-button:hover { color: var(--cyan); }
.story-sentence { min-height: 52px; margin: 10px 0 0; color: var(--text); font-size: 14px; font-weight: 620; line-height: 1.5; }
.story-sentence .placeholder { color: var(--muted-2); font-weight: 500; }
.story-sentence .story-label { color: var(--muted-2); }
.story-sentence .story-value { color: var(--cyan); }
.feedback { display: flex; align-items: flex-start; gap: 8px; min-height: 27px; margin-top: 12px; color: var(--muted); font: 11px/1.4 "SFMono-Regular", Consolas, monospace; }
.feedback-icon { display: inline-grid; flex: 0 0 16px; width: 16px; height: 16px; place-items: center; border: 1px solid currentColor; border-radius: 50%; font-size: 9px; }
.feedback-success { color: var(--green); }
.feedback-error { color: var(--red); }
.feedback-neutral { color: var(--muted-2); }

.bdd-instruction { display: flex; align-items: flex-start; gap: 10px; margin: 20px 0 17px; padding: 12px 13px; border: 1px solid var(--line); border-radius: 9px; background: var(--surface); }
.terminal-prompt { color: var(--green); font: 11px "SFMono-Regular", Consolas, monospace; }
.bdd-instruction p { margin: 0; color: var(--muted); font-size: 11px; line-height: 1.45; }
.bdd-instruction strong { color: var(--text); }
.bdd-layout { display: grid; grid-template-columns: 1fr 1.14fr; gap: 16px; }
.library-label { margin: 0 0 8px; color: var(--muted-2); font: 9px "SFMono-Regular", Consolas, monospace; letter-spacing: .1em; text-transform: uppercase; }
.block-library { min-width: 0; max-height: 330px; padding-right: 6px; overflow: auto; }
.block-library::-webkit-scrollbar { width: 4px; }
.block-library::-webkit-scrollbar-thumb { border-radius: 8px; background: var(--line-strong); }
.logic-block { display: flex; align-items: center; width: 100%; gap: 7px; margin-bottom: 7px; padding: 9px 9px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--muted); text-align: left; font: 10px/1.25 "SFMono-Regular", Consolas, monospace; transition: border-color .15s ease, background .15s ease, transform .15s ease; }
.logic-block:hover { border-color: var(--blue); background: var(--surface-raised); transform: translateX(2px); }
.logic-block:active { cursor: grabbing; transform: scale(.98); }
.block-keyword { flex: 0 0 auto; font-weight: 700; }
.given-block .block-keyword { color: var(--purple); }
.when-block .block-keyword { color: var(--blue-bright); }
.then-block .block-keyword { color: var(--green); }
.drag-handle { margin-left: auto; color: var(--muted-2); font-size: 14px; line-height: 1; }
.scenario-builder { min-width: 0; }
.scenario-toolbar { display: flex; align-items: center; justify-content: space-between; }
.scenario-toolbar .library-label { margin: 0; }
.ghost-button { padding: 0; border: 0; background: transparent; color: var(--muted-2); font: 10px "SFMono-Regular", Consolas, monospace; }
.ghost-button:hover { color: var(--red); }
.drop-zone { display: flex; min-height: 235px; flex-direction: column; justify-content: center; gap: 7px; margin-top: 8px; padding: 12px; border: 1px dashed var(--line-strong); border-radius: 10px; background: color-mix(in srgb, var(--surface) 75%, transparent); outline: none; transition: border-color .2s ease, background .2s ease; }
.drop-zone.is-over, .drop-zone:focus { border-color: var(--blue); background: color-mix(in srgb, var(--blue) 7%, var(--surface)); }
.drop-placeholder { display: grid; place-items: center; gap: 9px; color: var(--muted-2); font: 10px/1.4 "SFMono-Regular", Consolas, monospace; text-align: center; }
.plus-circle { display: grid; width: 28px; height: 28px; place-items: center; border: 1px solid var(--line-strong); border-radius: 50%; color: var(--muted); font-size: 16px; }
.scenario-token { position: relative; display: flex; align-items: center; gap: 7px; min-height: 48px; padding: 8px 25px 8px 10px; border: 1px solid var(--line); border-radius: 7px; background: var(--surface-raised); color: var(--text); font: 10px/1.3 "SFMono-Regular", Consolas, monospace; cursor: grab; animation: token-in .25s var(--ease); }
.scenario-token:hover { border-color: var(--blue); }
.scenario-token .token-order { display: grid; width: 18px; height: 18px; flex: 0 0 18px; place-items: center; border-radius: 5px; background: var(--surface); color: var(--muted-2); font-size: 9px; }
.scenario-token .token-kind { color: var(--muted-2); }
.scenario-token[data-kind="given"] { border-left: 2px solid var(--purple); }
.scenario-token[data-kind="given"] .token-kind { color: var(--purple); }
.scenario-token[data-kind="when"] { border-left: 2px solid var(--blue-bright); }
.scenario-token[data-kind="when"] .token-kind { color: var(--blue-bright); }
.scenario-token[data-kind="then"] { border-left: 2px solid var(--green); }
.scenario-token[data-kind="then"] .token-kind { color: var(--green); }
.remove-token { position: absolute; top: 4px; right: 7px; padding: 0; border: 0; background: transparent; color: var(--muted-2); font-size: 15px; line-height: 1; }
.remove-token:hover { color: var(--red); }
.validate-button { width: 100%; margin-top: 11px; }

.hint-strip { display: flex; align-items: center; gap: 10px; margin-top: 18px; padding: 13px 15px; border: 1px solid var(--line); border-radius: 10px; color: var(--muted); font-size: 11px; }
.hint-strip p { margin: 0; }
.hint-strip strong { color: var(--text); }
.hint-icon { color: var(--yellow); }

.challenge-section { background: var(--bg-deep); }
.challenge-heading { display: flex; justify-content: space-between; align-items: end; gap: 30px; margin-bottom: 38px; }
.challenge-badge { display: flex; align-items: center; gap: 12px; padding: 10px 13px; border: 1px solid var(--line); border-radius: 9px; color: var(--muted-2); font: 9px "SFMono-Regular", Consolas, monospace; text-transform: uppercase; }
.challenge-badge strong { color: var(--cyan); font-size: 11px; }
.challenge-card { display: grid; grid-template-columns: 1fr 1fr; overflow: hidden; border: 1px solid var(--line-strong); border-radius: var(--radius-lg); background: var(--surface); box-shadow: var(--shadow); }
.challenge-context, .challenge-task { padding: 34px; }
.challenge-context { position: relative; overflow: hidden; border-right: 1px solid var(--line); background: linear-gradient(145deg, color-mix(in srgb, var(--red) 7%, var(--surface)), var(--surface)); }
.challenge-context::after { position: absolute; right: -90px; bottom: -120px; width: 280px; height: 280px; border: 1px solid color-mix(in srgb, var(--red) 20%, transparent); border-radius: 50%; content: ""; box-shadow: 0 0 0 30px color-mix(in srgb, var(--red) 4%, transparent); }
.challenge-icon { display: grid; width: 40px; height: 40px; margin-bottom: 26px; place-items: center; border: 1px solid var(--red); border-radius: 11px; color: var(--red); font-size: 21px; }
.challenge-context .overline { color: var(--red); }
.challenge-context h3 { position: relative; z-index: 1; max-width: 450px; margin: 16px 0 14px; font-size: 23px; letter-spacing: -.035em; line-height: 1.3; }
.challenge-context > p:not(.overline) { position: relative; z-index: 1; max-width: 420px; margin: 0; color: var(--muted); font-size: 13px; }
.ambiguity-tags { position: relative; z-index: 1; display: flex; flex-wrap: wrap; gap: 7px; margin-top: 28px; }
.ambiguity-tags span { padding: 6px 8px; border: 1px solid color-mix(in srgb, var(--red) 23%, var(--line)); border-radius: 6px; color: var(--red); font: 9px "SFMono-Regular", Consolas, monospace; }
.task-header { display: flex; align-items: center; gap: 12px; }
.task-number { display: grid; width: 30px; height: 30px; place-items: center; border: 1px solid var(--cyan); border-radius: 8px; color: var(--cyan); font: 11px "SFMono-Regular", Consolas, monospace; }
.task-header .overline { color: var(--muted-2); }
.task-header h3 { margin: 2px 0 0; font-size: 18px; }
.challenge-task > p { margin: 22px 0; color: var(--muted); font-size: 13px; }
.success-criteria { display: grid; gap: 6px; padding: 13px; border: 1px solid color-mix(in srgb, var(--green) 24%, var(--line)); border-radius: 9px; background: color-mix(in srgb, var(--green) 5%, var(--surface)); }
.success-criteria span:first-child { color: var(--green); font: 9px "SFMono-Regular", Consolas, monospace; letter-spacing: .08em; text-transform: uppercase; }
.success-criteria span:last-child { color: var(--muted); font-size: 11px; }
.challenge-button { width: 100%; margin-top: 24px; }
.challenge-feedback { min-height: 39px; margin-top: 13px; color: var(--muted); font: 11px/1.45 "SFMono-Regular", Consolas, monospace; }
.challenge-feedback.is-error { color: var(--red); }
.challenge-feedback.is-success { color: var(--green); }
.approval-panel { display: none; align-items: center; gap: 22px; margin-top: 22px; padding: 24px 28px; border: 1px solid color-mix(in srgb, var(--green) 45%, var(--line)); border-radius: var(--radius-md); background: linear-gradient(105deg, color-mix(in srgb, var(--green) 10%, var(--surface)), var(--surface)); animation: success-in .65s var(--ease) both; }
.approval-panel.is-visible { display: flex; }
.approval-orbit { display: grid; width: 58px; height: 58px; flex: 0 0 58px; place-items: center; border: 1px solid var(--green); border-radius: 50%; color: var(--green); font-size: 26px; box-shadow: 0 0 0 8px color-mix(in srgb, var(--green) 8%, transparent), 0 0 30px color-mix(in srgb, var(--green) 18%, transparent); animation: orbit-pulse 1.8s ease-in-out infinite; }
.approval-panel h3 { margin: 3px 0 2px; font-size: 18px; }
.approval-panel p:not(.eyebrow) { margin: 0; color: var(--muted); font-size: 12px; }
.approval-score { margin-left: auto; text-align: right; }
.approval-score strong { display: block; color: var(--green); font-size: 27px; line-height: 1; }
.approval-score span { color: var(--muted-2); font: 9px "SFMono-Regular", Consolas, monospace; text-transform: uppercase; }

.site-footer { border-top: 1px solid var(--line); background: var(--bg); }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; min-height: 75px; color: var(--muted-2); font-size: 11px; }
.footer-brand { display: flex; align-items: center; gap: 9px; color: var(--muted); }
.footer-brand .brand-mark { width: 25px; height: 25px; border-radius: 6px; font-size: 9px; }
.footer-inner p { margin: 0; }
.footer-year { font: 10px "SFMono-Regular", Consolas, monospace; }

.reveal { opacity: 0; transform: translateY(15px); transition: opacity .65s ease, transform .65s var(--ease); }
.reveal.is-visible { opacity: 1; transform: translateY(0); }

@keyframes blink { 50% { opacity: 0; } }
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-8px); } }
@keyframes token-in { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: translateY(0); } }
@keyframes success-in { from { opacity: 0; transform: translateY(12px) scale(.99); } to { opacity: 1; transform: translateY(0) scale(1); } }
@keyframes orbit-pulse { 50% { box-shadow: 0 0 0 12px color-mix(in srgb, var(--green) 3%, transparent), 0 0 38px color-mix(in srgb, var(--green) 24%, transparent); } }

:focus-visible { outline: 2px solid var(--cyan); outline-offset: 3px; }

@media (max-width: 1000px) {
  .hero-grid { grid-template-columns: 1fr; gap: 35px; }
  .hero-visual { min-height: 300px; max-width: 600px; }
  .hero h1 { max-width: 760px; }
  .analogy-grid { grid-template-columns: repeat(2, 1fr); }
  .bridge-card { grid-column: 1 / -1; min-height: 0; }
  .simulator-shell { grid-template-columns: 1fr; }
  .story-panel { border-right: 0; border-bottom: 1px solid var(--line); }
  .story-controls { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 700px) {
  .container { width: min(100% - 32px, 560px); }
  .section-pad { padding: 78px 0; }
  .header-inner { min-height: 65px; }
  .main-nav { display: none; }
  .brand { min-width: 0; }
  .hero { padding-top: 65px; }
  .hero h1 { font-size: clamp(40px, 12vw, 61px); }
  .hero-description { font-size: 14px; }
  .hero-actions { flex-wrap: wrap; gap: 17px; }
  .hero-visual { min-height: 240px; margin-top: 16px; }
  .code-window { transform: none; }
  .code-lines { padding: 20px 13px 23px; font-size: 9px; line-height: 2.5; }
  .code-lines i { width: 22px; }
  .floating-chip { font-size: 8px; }
  .chip-context { left: -1%; }
  .chip-check { right: -1%; }
  .rap-callout { grid-template-columns: auto 1fr; gap: 13px; margin-top: 32px; padding: 17px; }
  .rap-meta { grid-column: 2; }
  .rap-text { font-size: 12px; }
  .section-heading, .challenge-heading { display: block; margin-bottom: 34px; }
  .section-intro { margin-top: 18px; }
  .analogy-grid { grid-template-columns: 1fr; }
  .concept-card { min-height: 0; }
  .bridge-card { grid-column: auto; min-height: 0; }
  .anatomy-section { margin-top: 57px; }
  .anatomy-grid { grid-template-columns: 1fr; }
  .anatomy-item, .anatomy-item + .anatomy-item { padding: 18px 0; border-left: 0; }
  .anatomy-item + .anatomy-item { border-top: 1px solid var(--line); }
  .lab-status, .challenge-badge { display: inline-block; margin-top: 18px; }
  .simulator-panel { padding: 21px 16px; }
  .panel-header { gap: 8px; }
  .syntax-tag { font-size: 8px; }
  .panel-description { min-height: 0; margin: 18px 0; }
  .story-controls { grid-template-columns: 1fr; }
  .bdd-layout { grid-template-columns: 1fr; }
  .block-library { max-height: 250px; padding-right: 0; }
  .drop-zone { min-height: 200px; }
  .challenge-card { grid-template-columns: 1fr; }
  .challenge-context { border-right: 0; border-bottom: 1px solid var(--line); }
  .challenge-context, .challenge-task { padding: 24px 20px; }
  .challenge-context h3 { font-size: 20px; }
  .approval-panel { align-items: flex-start; flex-wrap: wrap; padding: 22px 18px; }
  .approval-score { width: 100%; margin-left: 0; text-align: left; }
  .footer-inner { flex-wrap: wrap; justify-content: center; padding: 20px 0; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
}

/* --------------------------------------------------------------------------
   Profundización: requisitos y arquitectura.
   -------------------------------------------------------------------------- */

.requirements-section { background: var(--surface-soft); }
.requirement-primer { display: grid; grid-template-columns: 1fr; gap: 1px; overflow: hidden; border: 1px solid var(--line); border-radius: var(--radius-lg); background: var(--line); }
.requirement-primer > div { padding: 24px; background: var(--surface); }
.primer-number { display: inline-grid; width: 44px; height: 28px; place-items: center; border: 1px solid color-mix(in srgb, var(--green) 44%, var(--line)); border-radius: 7px; color: var(--green); font: 700 10px "SFMono-Regular", Consolas, monospace; }
.primer-purple { border-color: color-mix(in srgb, var(--purple) 44%, var(--line)); color: var(--purple); }
.requirement-primer h3 { margin: 20px 0 7px; font-size: 19px; letter-spacing: -.025em; }
.requirement-primer p { margin: 0; color: var(--muted); font-size: 13px; }
.requirement-primer strong { color: var(--text); }
.requirements-table-wrap { margin-top: 18px; overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius-lg); background: var(--surface); }
.requirements-table { width: 100%; min-width: 760px; border-collapse: collapse; font-size: 12px; }
.requirements-table th { padding: 13px 15px; border-bottom: 1px solid var(--line-strong); color: var(--muted-2); font: 9px "SFMono-Regular", Consolas, monospace; letter-spacing: .1em; text-align: left; text-transform: uppercase; }
.requirements-table td { padding: 15px; border-bottom: 1px solid var(--line); color: var(--muted); vertical-align: top; }
.requirements-table tr:last-child td { border-bottom: 0; }
.requirements-table td:nth-child(2), .requirements-table td:nth-child(3) { color: var(--text); }
.table-tag { display: inline-block; padding: 4px 6px; border-radius: 5px; font: 10px "SFMono-Regular", Consolas, monospace; }
.tag-functional { background: color-mix(in srgb, var(--green) 11%, transparent); color: var(--green); }
.tag-nonfunctional { background: color-mix(in srgb, var(--purple) 11%, transparent); color: var(--purple); }
.requirement-details-grid { display: grid; grid-template-columns: 1fr; gap: 16px; margin-top: 16px; }
.detail-card { padding: 24px; border: 1px solid var(--line); border-radius: var(--radius-lg); background: var(--surface); }
.functional-detail { border-top: 2px solid var(--green); }
.nonfunctional-detail { border-top: 2px solid var(--purple); }
.detail-card-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.detail-kicker { color: var(--muted-2); font: 10px "SFMono-Regular", Consolas, monospace; }
.detail-card h3 { margin: 22px 0 18px; font-size: 19px; letter-spacing: -.025em; }
.check-list { display: grid; gap: 0; margin: 0; padding: 0; list-style: none; }
.check-list li { display: grid; grid-template-columns: 28px 1fr; gap: 10px; padding: 12px 0; border-top: 1px solid var(--line); }
.check-list li > span { color: var(--green); font: 10px "SFMono-Regular", Consolas, monospace; }
.check-list strong, .check-list small { display: block; }
.check-list strong { font-size: 12px; }
.check-list small { margin-top: 3px; color: var(--muted); font-size: 11px; }
.spec-example { margin-top: 20px; padding: 13px 14px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface-soft); color: var(--muted); font-size: 11px; }
.spec-example p { margin: 5px 0 0; }
.bad-requirement { color: var(--red); }
.good-requirement { color: var(--green); }
.quality-catalog { display: grid; gap: 0; }
.quality-catalog > div { display: grid; grid-template-columns: 112px 1fr; gap: 10px; padding: 10px 0; border-top: 1px solid var(--line); }
.quality-catalog b { color: var(--text); font-size: 11px; }
.quality-catalog span { color: var(--muted); font-size: 11px; }
.exercise-zone { margin-top: 55px; padding-top: 25px; border-top: 1px solid var(--line-strong); }
.exercise-heading { display: flex; align-items: end; justify-content: space-between; gap: 20px; margin-bottom: 18px; }
.exercise-heading h3 { margin: 8px 0 0; font-size: 22px; letter-spacing: -.03em; }
.exercise-count { color: var(--muted-2); font: 10px "SFMono-Regular", Consolas, monospace; }
.exercise-grid { display: grid; grid-template-columns: 1fr; gap: 10px; }
.exercise-card { border: 1px solid var(--line); border-radius: 12px; background: var(--surface); }
.exercise-card summary { display: grid; grid-template-columns: 32px 1fr 18px; align-items: center; gap: 12px; padding: 15px; cursor: pointer; list-style: none; }
.exercise-card summary::-webkit-details-marker { display: none; }
.exercise-card summary > b { color: var(--cyan); font-size: 20px; font-weight: 400; transition: transform .2s ease; }
.exercise-card[open] summary > b { transform: rotate(45deg); }
.exercise-number { color: var(--blue-bright); font: 10px "SFMono-Regular", Consolas, monospace; }
.exercise-card summary strong, .exercise-card summary small { display: block; }
.exercise-card summary strong { font-size: 12px; }
.exercise-card summary small { margin-top: 2px; color: var(--muted-2); font-size: 10px; }
.exercise-card > p { margin: 0; padding: 0 15px 13px 59px; color: var(--muted); font-size: 12px; }
.answer { margin: 0 15px 15px 59px; padding: 11px 12px; border-left: 2px solid var(--cyan); background: color-mix(in srgb, var(--cyan) 6%, transparent); }
.answer span { color: var(--cyan); font: 9px "SFMono-Regular", Consolas, monospace; letter-spacing: .1em; text-transform: uppercase; }
.answer p { margin: 5px 0 0; color: var(--muted); font-size: 11px; }

.platform-decisions { margin-top: 22px; padding: 24px; border: 1px solid var(--line-strong); border-radius: var(--radius-lg); background: linear-gradient(140deg, color-mix(in srgb, var(--blue) 8%, var(--surface-soft)), var(--surface-soft) 48%); }
.platform-heading { display: grid; grid-template-columns: 1fr; gap: 12px; align-items: end; }
.platform-heading h3 { max-width: 650px; margin: 9px 0 0; font-size: clamp(23px, 4vw, 32px); letter-spacing: -.035em; }
.platform-heading > p { max-width: 460px; margin: 0; color: var(--muted); font-size: 12px; }
.platform-grid { display: grid; grid-template-columns: 1fr; gap: 10px; margin-top: 22px; }
.platform-card { display: flex; min-width: 0; flex-direction: column; padding: 20px; border: 1px solid var(--line); border-top: 2px solid var(--blue); border-radius: 13px; background: var(--surface); }
.platform-card:nth-child(2) { border-top-color: var(--purple); }
.platform-card:nth-child(3) { border-top-color: var(--green); }
.platform-card-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 19px; }
.platform-index { color: var(--muted-2); font: 10px "SFMono-Regular", Consolas, monospace; }
.platform-icon { display: inline-grid; width: 31px; height: 31px; place-items: center; border: 1px solid color-mix(in srgb, var(--blue) 40%, var(--line)); border-radius: 8px; color: var(--blue-bright); font-size: 15px; }
.platform-card:nth-child(2) .platform-icon { border-color: color-mix(in srgb, var(--purple) 40%, var(--line)); color: var(--purple); }
.platform-card:nth-child(3) .platform-icon { border-color: color-mix(in srgb, var(--green) 40%, var(--line)); color: var(--green); }
.platform-card .overline { color: var(--muted-2); font-size: 9px; }
.platform-card h4 { margin: 6px 0 9px; font-size: 18px; }
.platform-card > p:not(.overline) { margin: 0; color: var(--muted); font-size: 11px; }
.platform-decision { display: grid; gap: 5px; margin-top: auto; padding-top: 19px; }
.platform-decision span { color: var(--cyan); font: 9px "SFMono-Regular", Consolas, monospace; letter-spacing: .08em; text-transform: uppercase; }
.platform-decision strong { color: var(--text); font-size: 10px; line-height: 1.5; }
.deployment-route { margin-top: 20px; padding-top: 20px; border-top: 1px solid var(--line); }
.route-heading { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 8px 18px; }
.route-heading span { color: var(--cyan); font: 10px "SFMono-Regular", Consolas, monospace; letter-spacing: .1em; text-transform: uppercase; }
.route-heading p { margin: 0; color: var(--muted-2); font-size: 11px; }
.deployment-flow { display: grid; grid-template-columns: 1fr; gap: 8px; align-items: center; margin-top: 12px; padding: 15px; border: 1px solid color-mix(in srgb, var(--blue) 27%, var(--line)); border-radius: var(--radius-md); background: color-mix(in srgb, var(--blue) 6%, var(--surface)); }
.flow-step { display: grid; grid-template-columns: 28px 1fr; column-gap: 8px; align-items: center; }
.flow-step > span { grid-row: 1 / span 2; color: var(--blue-bright); font: 10px "SFMono-Regular", Consolas, monospace; }
.flow-step strong { font-size: 12px; }
.flow-step small { color: var(--muted); font-size: 10px; }
.deployment-flow > b { justify-self: center; color: var(--cyan); font-size: 18px; transform: rotate(90deg); }

.architecture-section { background: var(--bg); }
.architecture-board { display: grid; gap: 8px; padding: 18px; border: 1px solid var(--line-strong); border-radius: var(--radius-lg); background: radial-gradient(circle at 50% 0%, color-mix(in srgb, var(--blue) 12%, transparent), transparent 42%), var(--surface-soft); box-shadow: var(--shadow); }
.arch-layer, .arch-foundation, .arch-side-note { border: 1px solid var(--line); border-radius: 12px; background: var(--surface); }
.arch-layer { padding: 15px; text-align: center; }
.layer-label { display: block; margin-bottom: 6px; color: var(--muted-2); font: 9px "SFMono-Regular", Consolas, monospace; letter-spacing: .1em; text-transform: uppercase; }
.arch-layer > strong, .arch-foundation > strong { display: block; font-size: 13px; }
.arch-layer > small, .arch-foundation > small { display: block; margin-top: 4px; color: var(--muted); font-size: 10px; }
.arch-users { border-color: color-mix(in srgb, var(--cyan) 32%, var(--line)); }
.arch-edge { border-color: color-mix(in srgb, var(--blue) 32%, var(--line)); }
.arch-app { border-color: color-mix(in srgb, var(--green) 30%, var(--line)); }
.arch-data { border-color: color-mix(in srgb, var(--purple) 30%, var(--line)); }
.arch-arrow { justify-self: center; color: var(--cyan); font-size: 18px; line-height: 1; }
.arch-service-row { display: grid; grid-template-columns: 1fr; gap: 7px; margin-top: 10px; }
.arch-service-row > div { padding: 10px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface-soft); }
.arch-service-row strong, .arch-service-row small { display: block; }
.arch-service-row strong { color: var(--text); font-size: 11px; }
.arch-service-row small { margin-top: 3px; color: var(--muted-2); font-size: 9px; }
.arch-side-note { display: grid; grid-template-columns: 22px 1fr; column-gap: 8px; padding: 13px; }
.arch-side-note > span { grid-row: 1 / span 2; color: var(--yellow); font-size: 16px; }
.arch-side-note strong { font-size: 11px; }
.arch-side-note small { color: var(--muted); font-size: 10px; }
.arch-ops > span { color: var(--green); }
.arch-foundation { padding: 15px; border-color: color-mix(in srgb, var(--yellow) 32%, var(--line)); background: color-mix(in srgb, var(--yellow) 5%, var(--surface)); text-align: center; }
.architecture-explain-grid { display: grid; min-width: 0; grid-template-columns: minmax(0, 1fr); gap: 12px; margin-top: 16px; }
.architecture-card { min-width: 0; padding: 22px; border: 1px solid var(--line); border-radius: var(--radius-md); background: var(--surface); }
.architecture-card .card-index { color: var(--cyan); }
.architecture-card h3 { margin: 17px 0 13px; font-size: 18px; letter-spacing: -.025em; }
.architecture-card ol { margin: 0; padding-left: 20px; color: var(--muted); font-size: 11px; }
.architecture-card li + li { margin-top: 9px; }
.decision-list { display: grid; gap: 10px; margin: 0; padding: 0; list-style: none; color: var(--muted); font-size: 11px; }
.decision-list b { color: var(--text); }
.architecture-prompt > p:not(.prompt-warning) { margin: 0; color: var(--muted); font-size: 11px; }
.architecture-prompt pre { max-width: 100%; overflow-x: auto; margin: 13px 0; padding: 13px; border: 1px solid var(--line); border-radius: 9px; background: var(--bg-deep); color: var(--cyan); font: 10px/1.65 "SFMono-Regular", Consolas, monospace; }
.architecture-prompt code { font: inherit; }
.prompt-warning { padding: 10px; border-left: 2px solid var(--yellow); background: color-mix(in srgb, var(--yellow) 5%, transparent); color: var(--muted-2) !important; font: 10px/1.45 "SFMono-Regular", Consolas, monospace !important; }
.architecture-takeaway { display: flex; align-items: flex-start; gap: 12px; margin-top: 20px; padding: 17px; border: 1px solid color-mix(in srgb, var(--cyan) 30%, var(--line)); border-radius: var(--radius-md); background: color-mix(in srgb, var(--cyan) 5%, var(--surface)); }
.takeaway-icon { display: grid; width: 24px; height: 24px; flex: 0 0 24px; place-items: center; border: 1px solid var(--cyan); border-radius: 50%; color: var(--cyan); font-size: 12px; }
.architecture-takeaway p { margin: 0; color: var(--muted); font-size: 12px; }
.architecture-takeaway strong { color: var(--text); }

@media (min-width: 700px) {
  .requirement-primer { grid-template-columns: 1fr 1fr; }
  .requirement-primer > div { padding: 28px; }
  .requirement-details-grid { grid-template-columns: 1fr 1fr; }
  .exercise-grid { grid-template-columns: repeat(3, 1fr); }
  .exercise-card summary { min-height: 88px; }
  .platform-heading { grid-template-columns: minmax(0, 1.3fr) minmax(260px, .7fr); }
  .platform-grid { grid-template-columns: repeat(2, 1fr); }
  .platform-card:last-child { grid-column: 1 / -1; }
  .deployment-flow { grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr; }
  .deployment-flow > b { transform: none; }
  .arch-service-row { grid-template-columns: repeat(3, 1fr); }
  .arch-side-note { min-height: 70px; }
  .architecture-explain-grid { grid-template-columns: repeat(2, 1fr); }
  .architecture-prompt { grid-column: 1 / -1; }
}

@media (min-width: 700px) and (max-width: 999px) {
  .header-inner { gap: 10px; }
  .brand { min-width: 140px; }
  .main-nav { gap: 10px; font-size: 11px; }
}

@media (min-width: 1000px) {
  .platform-grid { grid-template-columns: repeat(3, 1fr); }
  .platform-card:last-child { grid-column: auto; }
  .architecture-board { grid-template-columns: 1fr 46px 1fr; align-items: center; padding: 28px; }
  .arch-layer, .arch-foundation { grid-column: 1 / -1; }
  .arch-arrow { grid-column: 2; }
  .arch-side-note { grid-column: 1; }
  .arch-ops { grid-column: 3; grid-row: 9; }
  .arch-integrations { grid-row: 9; }
  .arch-foundation { grid-row: 11; }
  .architecture-explain-grid { grid-template-columns: repeat(3, 1fr); }
  .architecture-prompt { grid-column: auto; }
}

/* --------------------------------------------------------------------------
   Extensiones pedagógicas y responsive contract
   La base de esta capa es mobile-first: una columna, controles táctiles y
   contenido legible; las columnas se agregan progresivamente con min-width.
   -------------------------------------------------------------------------- */

body { overflow-x: hidden; }
img { display: block; max-width: 100%; height: auto; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }

.mobile-menu-toggle { display: inline-flex; width: 44px; height: 44px; flex: 0 0 44px; flex-direction: column; align-items: center; justify-content: center; gap: 4px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface-soft); color: var(--muted); }
.mobile-menu-toggle span { display: block; width: 17px; height: 1px; border-radius: 2px; background: currentColor; transition: transform .2s ease, opacity .2s ease; }
.mobile-menu-toggle[aria-expanded="true"] span:first-child { transform: translateY(5px) rotate(45deg); }
.mobile-menu-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.mobile-menu-toggle[aria-expanded="true"] span:last-child { transform: translateY(-5px) rotate(-45deg); }
.mobile-menu-toggle:hover { border-color: var(--blue); color: var(--text); }

.context-section { background: var(--bg); }
.context-heading { margin-bottom: 38px; }
.context-grid { display: grid; grid-template-columns: 1fr; gap: 28px; align-items: center; }
.context-copy { display: grid; gap: 0; }
.context-principle { display: grid; grid-template-columns: 36px 1fr; gap: 14px; padding: 19px 0; border-top: 1px solid var(--line); }
.context-principle:last-child { border-bottom: 1px solid var(--line); }
.principle-mark { color: var(--cyan); font: 11px "SFMono-Regular", Consolas, monospace; }
.context-principle h3 { margin: 0; font-size: 16px; letter-spacing: -.02em; }
.context-principle p { margin: 6px 0 0; color: var(--muted); font-size: 12px; line-height: 1.6; }
.context-figure { margin: 0; padding: 7px; border: 1px solid var(--line); border-radius: var(--radius-lg); background: var(--surface); box-shadow: var(--shadow); }
.context-figure img { width: 100%; border-radius: 18px; }
.context-figure figcaption { display: flex; align-items: center; gap: 8px; padding: 11px 10px 5px; color: var(--muted-2); font: 10px "SFMono-Regular", Consolas, monospace; }
.caption-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--cyan); }
.quality-strip { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; margin-top: 32px; overflow: hidden; border: 1px solid var(--line); border-radius: var(--radius-md); background: var(--line); }
.quality-strip > div { display: grid; grid-template-columns: 28px 1fr; grid-template-rows: auto auto; column-gap: 9px; padding: 15px 13px; background: var(--surface); }
.quality-icon { display: grid; width: 26px; height: 26px; grid-row: 1 / -1; place-items: center; border: 1px solid color-mix(in srgb, var(--cyan) 38%, var(--line)); border-radius: 7px; color: var(--cyan); font: 11px "SFMono-Regular", Consolas, monospace; }
.quality-strip strong { font-size: 12px; }
.quality-strip small { color: var(--muted-2); font-size: 10px; }

.bdd-explainer { display: grid; grid-template-columns: 1fr; gap: 20px; margin-top: 40px; padding: 20px; border: 1px solid var(--line); border-radius: var(--radius-lg); background: linear-gradient(125deg, color-mix(in srgb, var(--purple) 7%, var(--surface)), var(--surface)); }
.bdd-explainer-copy h3 { margin: 9px 0 9px; font-size: 20px; letter-spacing: -.03em; }
.bdd-explainer-copy > p:not(.eyebrow) { margin: 0; color: var(--muted); font-size: 12px; }
.bdd-rule { display: grid; gap: 5px; margin-top: 20px; padding: 11px 12px; border-left: 2px solid var(--purple); background: color-mix(in srgb, var(--purple) 7%, transparent); }
.bdd-rule span { color: var(--purple); font: 9px "SFMono-Regular", Consolas, monospace; letter-spacing: .1em; text-transform: uppercase; }
.bdd-rule strong { font-size: 12px; }
.bdd-figure { margin: 0; padding: 4px; border: 1px solid var(--line); border-radius: 15px; background: var(--surface-soft); }
.bdd-figure img { width: 100%; border-radius: 12px; }
.analyzer-panel { margin-top: 18px; padding: 20px; border: 1px solid var(--line-strong); border-radius: var(--radius-lg); background: var(--surface-soft); box-shadow: var(--shadow); }
.analyzer-header { margin-bottom: 18px; }
.syntax-yellow { border-color: color-mix(in srgb, var(--yellow) 35%, var(--line)); color: var(--yellow); }
.analyzer-panel .panel-description { min-height: 0; margin: 0 0 17px; }
.analyzer-input-row { display: grid; grid-template-columns: 1fr; gap: 10px; }
.analyzer-input-row textarea { width: 100%; min-height: 100px; resize: vertical; padding: 12px; border: 1px solid var(--line); border-radius: 9px; outline: none; background: var(--surface); color: var(--text); font: 12px/1.55 "SFMono-Regular", Consolas, monospace; }
.analyzer-input-row textarea::placeholder { color: var(--muted-2); }
.analyzer-input-row textarea:focus { border-color: var(--blue); box-shadow: 0 0 0 3px color-mix(in srgb, var(--blue) 16%, transparent); }
.analyzer-input-row .button { width: 100%; }
.sample-prompts { display: flex; flex-wrap: wrap; align-items: center; gap: 7px; margin-top: 11px; color: var(--muted-2); font: 10px "SFMono-Regular", Consolas, monospace; }
.sample-prompts button { min-height: 32px; padding: 0 9px; border: 1px solid var(--line); border-radius: 6px; background: var(--surface); color: var(--muted); font: inherit; }
.sample-prompts button:hover { border-color: var(--blue); color: var(--text); }
.analysis-output { min-height: 102px; margin-top: 17px; padding: 14px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); }
.analysis-empty { display: flex; min-height: 72px; align-items: center; justify-content: center; gap: 9px; color: var(--muted-2); font: 11px "SFMono-Regular", Consolas, monospace; }
.analysis-empty p { margin: 0; }
.scan-icon { color: var(--cyan); font-size: 21px; }
.analysis-summary { display: flex; align-items: start; justify-content: space-between; gap: 15px; }
.analysis-summary h4 { margin: 0; font-size: 14px; }
.analysis-summary p { margin: 4px 0 0; color: var(--muted); font-size: 11px; }
.analysis-score { flex: 0 0 auto; color: var(--yellow); font: 700 19px "SFMono-Regular", Consolas, monospace; }
.analysis-score.is-good { color: var(--green); }
.analysis-checks { display: grid; grid-template-columns: 1fr; gap: 7px; margin-top: 14px; }
.analysis-check { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 11px; }
.analysis-check b { display: grid; width: 18px; height: 18px; flex: 0 0 18px; place-items: center; border-radius: 5px; background: color-mix(in srgb, var(--red) 12%, transparent); color: var(--red); font-size: 10px; }
.analysis-check.is-good b { background: color-mix(in srgb, var(--green) 12%, transparent); color: var(--green); }
.analysis-check strong { color: var(--text); font-weight: 600; }
.analysis-tip { margin: 13px 0 0; padding-top: 11px; border-top: 1px solid var(--line); color: var(--muted-2); font: 10px/1.5 "SFMono-Regular", Consolas, monospace; }

/* Mobile-first defaults. */
.container { width: min(100% - 32px, 1160px); }
.section-pad { padding: 72px 0; }
.header-inner { min-height: 64px; gap: 10px; }
.brand { min-width: 0; }
.brand small { font-size: 9px; }
.main-nav { position: absolute; top: calc(100% + 1px); right: 16px; left: 16px; display: grid; gap: 0; visibility: hidden; padding: 8px; border: 1px solid var(--line); border-radius: 12px; background: color-mix(in srgb, var(--surface) 96%, transparent); box-shadow: var(--shadow); opacity: 0; transform: translateY(-8px); transition: opacity .2s ease, transform .2s ease, visibility .2s ease; }
.main-nav.is-open { visibility: visible; opacity: 1; transform: translateY(0); }
.main-nav a { min-height: 44px; display: flex; align-items: center; padding: 0 12px; border-radius: 8px; }
.main-nav a::after { display: none; }
.main-nav a:hover, .main-nav a.is-active { background: var(--surface-raised); }
.hero { padding-top: 64px; }
.hero-grid { grid-template-columns: 1fr; gap: 28px; min-height: 0; }
.hero h1 { font-size: clamp(40px, 12vw, 62px); }
.hero-visual { min-height: 240px; }
.code-window { transform: none; }
.rap-callout { grid-template-columns: auto 1fr; gap: 13px; margin-top: 32px; padding: 17px; }
.rap-meta { grid-column: 2; }
.section-heading, .challenge-heading { display: block; margin-bottom: 34px; }
.section-heading h2, .challenge-heading h2 { font-size: clamp(32px, 9vw, 49px); }
.section-intro { margin-top: 17px; }
.analogy-grid { grid-template-columns: 1fr; }
.concept-card { min-height: 0; }
.bridge-card { min-height: 0; }
.anatomy-grid { grid-template-columns: 1fr; }
.anatomy-item, .anatomy-item + .anatomy-item { padding: 18px 0; border-left: 0; }
.anatomy-item + .anatomy-item { border-top: 1px solid var(--line); }
.lab-status, .challenge-badge { display: inline-block; margin-top: 18px; }
.simulator-shell { grid-template-columns: 1fr; }
.story-panel { border-right: 0; border-bottom: 1px solid var(--line); }
.simulator-panel { padding: 21px 16px; }
.story-controls { grid-template-columns: 1fr; }
.bdd-layout { grid-template-columns: 1fr; }
.block-library { max-height: 250px; padding-right: 0; }
.challenge-card { grid-template-columns: 1fr; }
.challenge-context { border-right: 0; border-bottom: 1px solid var(--line); }
.challenge-context, .challenge-task { padding: 24px 20px; }
.approval-panel { align-items: flex-start; flex-wrap: wrap; padding: 22px 18px; }
.approval-score { width: 100%; margin-left: 0; text-align: left; }
.footer-inner { flex-wrap: wrap; justify-content: center; padding: 20px 0; text-align: center; }
.logic-block, .ghost-button, .sample-prompts button { min-height: 44px; }

@media (min-width: 700px) {
  .container { width: min(100% - 48px, 1160px); }
  .section-pad { padding: 96px 0; }
  .header-inner { min-height: 72px; }
  .main-nav { position: static; display: flex; visibility: visible; gap: 22px; padding: 0; border: 0; background: transparent; box-shadow: none; opacity: 1; transform: none; }
  .main-nav a { min-height: 0; padding: 0; }
  .main-nav a::after { display: block; }
  .mobile-menu-toggle { display: none; }
  .hero { padding-top: 82px; }
  .hero h1 { font-size: clamp(46px, 7vw, 72px); }
  .hero-visual { min-height: 310px; }
  .rap-callout { grid-template-columns: auto 1fr auto; margin-top: 44px; padding: 20px 23px; }
  .rap-meta { grid-column: auto; }
  .section-heading, .challenge-heading { display: flex; align-items: end; justify-content: space-between; gap: 40px; }
  .section-heading h2, .challenge-heading h2 { font-size: clamp(35px, 5vw, 49px); }
  .analogy-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .bridge-card { grid-column: 1 / -1; }
  .anatomy-grid { grid-template-columns: repeat(3, 1fr); }
  .anatomy-item, .anatomy-item + .anatomy-item { padding: 22px 22px 22px 0; border-top: 0; }
  .anatomy-item + .anatomy-item { padding-left: 22px; border-left: 1px solid var(--line); }
  .context-grid { grid-template-columns: .82fr 1.18fr; gap: 32px; }
  .quality-strip { grid-template-columns: repeat(4, 1fr); }
  .bdd-explainer { grid-template-columns: .8fr 1.2fr; align-items: center; padding: 24px; }
  .analyzer-panel { padding: 25px; }
  .analyzer-input-row { grid-template-columns: 1fr auto; align-items: end; }
  .analyzer-input-row .button { width: auto; min-height: 100px; }
  .analysis-checks { grid-template-columns: repeat(2, 1fr); }
  .challenge-card { grid-template-columns: 1fr 1fr; }
  .challenge-context { border-right: 1px solid var(--line); border-bottom: 0; }
  .challenge-context, .challenge-task { padding: 30px; }
  .approval-panel { flex-wrap: nowrap; padding: 24px 28px; }
  .approval-score { width: auto; margin-left: auto; text-align: right; }
  .footer-inner { flex-wrap: nowrap; justify-content: space-between; padding: 0; text-align: left; }
}

@media (min-width: 1000px) {
  .section-pad { padding: 112px 0; }
  .hero { padding-top: 96px; }
  .hero-grid { grid-template-columns: minmax(0, 1.04fr) minmax(400px, .96fr); gap: 72px; min-height: 500px; }
  .hero h1 { font-size: clamp(52px, 5.5vw, 76px); }
  .hero-visual { min-height: 355px; }
  .analogy-grid { grid-template-columns: repeat(2, minmax(0, 1fr)) minmax(280px, .82fr); }
  .bridge-card { grid-column: auto; }
  .simulator-shell { grid-template-columns: .84fr 1.16fr; }
  .story-panel { border-right: 1px solid var(--line); border-bottom: 0; }
  .simulator-panel { padding: 30px; }
  .story-controls { grid-template-columns: 1fr; }
  .bdd-layout { grid-template-columns: 1fr 1.14fr; }
  .block-library { max-height: 330px; padding-right: 6px; }
  .challenge-context, .challenge-task { padding: 34px; }
}

@media (prefers-reduced-motion: reduce) {
  .mobile-menu-toggle span, .main-nav, .reveal { transition: none; }
}