*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

  :root {
    --ms-red: #883CF0;
    --ms-green: #7c3aed;
    --ms-blue: #8b5cf6;
    --ms-yellow: #b29dce;
    --ms-gray: #d6d6d6;
    --ms-dark: #191127;
    --ms-offwhite: #F5F4F0;
    --ms-white: #FFFFFF;
    --nav-h: 64px;
    --font-display: 'Syne', sans-serif;
    --font-serif: 'Instrument Serif', serif;
    --font-mono: 'DM Mono', monospace;
  }

  html { scroll-behavior: smooth; }

  body {
    font-family: var(--font-display);
    background: var(--ms-dark);
    color: var(--ms-white);
    overflow-x: hidden;
  }

  /* ─── NAV ─── */
  nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    height: var(--nav-h);
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 2.5rem;
    background: #180f26;
    backdrop-filter: blur(12px);
    border-bottom: 1px solid #3a1c63;
  }
  .nav-logo {
    display: flex; align-items: center; gap: 12px;
    font-size: 1rem; font-weight: 700; letter-spacing: -0.02em;
  }
  .ms-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 2px; width: 22px; height: 22px; }
  .ms-grid span { border-radius: 1px; }
  .nav-links { display: flex; gap: 2rem; }
  .nav-links a {
    font-size: 0.78rem; font-weight: 500; letter-spacing: 0.06em;
    text-transform: uppercase; color: rgba(255, 255, 255, 0.899);
    text-decoration: none; transition: color 0.2s;
  }
  .nav-links a:hover, .nav-links a.active { color: #883CF0; }

  /* ─── HERO ─── */
  .hero {
    min-height: 100vh; padding-top: var(--nav-h);
    display: flex; flex-direction: column; justify-content: center;
    position: relative; overflow: hidden;
    padding-left: 2.5rem; padding-right: 2.5rem;
  }
  .hero-bg {
    position: absolute; inset: 0; pointer-events: none; z-index: 0;
  }
  .hero-quad {
    position: absolute; width: 520px; height: 520px;
    top: 50%; left: 50%; transform: translate(-20%, -54%);
    display: grid; grid-template-columns: 1fr 1fr; gap: 6px;
    opacity: 0.12;
    animation: spin-slow 60s linear infinite;
  }
  .hero-quad span { border-radius: 4px; }
  @keyframes spin-slow { to { transform: translate(-20%, -54%) rotate(360deg); } }
  .hero-content { position: relative; z-index: 1; max-width: 900px; }
  .hero-eyebrow {
    font-size: 0.72rem; font-weight: 500; letter-spacing: 0.14em;
    text-transform: uppercase; color: rgba(255, 255, 255, 0.782);
    margin-bottom: 1.5rem;
    display: flex; align-items: center; gap: 10px;
  }
  .hero-eyebrow::before {
    content: ''; display: inline-block;
    width: 28px; height: 1px; background: var(--ms-blue);
  }
  h1 {
    font-size: clamp(3.2rem, 8vw, 7rem);
    font-weight: 800; line-height: 0.95;
    letter-spacing: -0.04em;
    margin-bottom: 2rem;
  }
  h1 em { font-family: var(--font-serif); font-weight: 400; font-style: italic; }
  .hero-sub {
    font-size: 1rem; font-weight: 400; color: rgba(255, 255, 255, 0.816);
    max-width: 480px; line-height: 1.7; margin-bottom: 3rem;
  }
  .hero-pills { display: flex; gap: 10px; flex-wrap: wrap; }
  .pill {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 8px 16px; border-radius: 100px;
    font-size: 0.76rem; font-weight: 600; letter-spacing: 0.04em;
    cursor: pointer; text-decoration: none;
    transition: transform 0.15s, opacity 0.15s;
  }
  .pill:hover { transform: translateY(-2px); opacity: 0.85; }
  .pill-red { background: var(--ms-red); color: white; }
  .pill-green { background: var(--ms-green); color: white; }
  .pill-blue { background: var(--ms-blue); color: white; }
  .pill-yellow { background: var(--ms-yellow); color: #111; }

  /* ─── SECTIONS ─── */
  section { padding: 7rem 2.5rem; border-top: 1px solid #3a1c63; }
  .section-label {
    font-size: 0.7rem; font-weight: 600; letter-spacing: 0.18em;
    text-transform: uppercase; color: rgba(255, 255, 255, 0.791);
    margin-bottom: 3rem; display: flex; align-items: center; gap: 10px;
  }
  .section-label span { display: inline-block; width: 24px; height: 1px; background: currentColor; }
  h2 {
    font-size: clamp(2rem, 4vw, 3.2rem); font-weight: 700;
    letter-spacing: -0.03em; line-height: 1.05;
    margin-bottom: 1rem;
  }
  h2 em { font-family: var(--font-serif); font-style: italic; font-weight: 400; }

  /* ─── COLOR SECTION ─── */
  #colors { background: #191127; }
  .colors-grid {
    display: grid; grid-template-columns: repeat(5, 1fr); gap: 1px;
    margin-top: 3rem; border-radius: 12px; overflow: hidden;
  }
  .color-tile {
    aspect-ratio: 1; display: flex; flex-direction: column;
    justify-content: flex-end; padding: 1.25rem;
    cursor: pointer; position: relative; overflow: hidden;
    transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
  }
  .color-tile:hover { transform: scale(1.03); z-index: 2; }
  .color-tile-name {
    font-size: 0.8rem; font-weight: 700; letter-spacing: 0.04em;
    text-transform: uppercase; margin-bottom: 3px;
  }
  .color-tile-hex {
    font-family: var(--font-mono); font-size: 0.75rem;
    opacity: 0.7;
  }
  .color-tile-copy {
    position: absolute; top: 1rem; right: 1rem;
    font-size: 0.6rem; font-weight: 600; letter-spacing: 0.08em;
    text-transform: uppercase; opacity: 0;
    background: rgba(0,0,0,0.25); padding: 4px 8px; border-radius: 4px;
    transition: opacity 0.2s;
  }
  .color-tile:hover .color-tile-copy { opacity: 1; }

  .color-info-panel {
    margin-top: 2rem;
    display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 1px;
    background: rgba(255,255,255,0.06); border-radius: 12px; overflow: hidden;
  }
  .color-info-cell {
    background: #23133a; padding: 1.5rem;
  }
  .color-info-label {
    font-size: 0.65rem; font-weight: 600; letter-spacing: 0.14em;
    text-transform: uppercase; color: rgba(255,255,255,0.3); margin-bottom: 6px;
  }
  .color-info-val { font-family: var(--font-mono); font-size: 0.9rem; }
  .color-swatch-big {
    width: 36px; height: 36px; border-radius: 8px; display: inline-block;
    vertical-align: middle; margin-right: 8px;
  }

  /* ─── LOGO SECTION ─── */
  #logo { background: #191127; }
  .logo-demo {
    margin-top: 3rem;
    display: grid; grid-template-columns: 1fr 1fr; gap: 1px;
    border-radius: 12px; overflow: hidden;
  }
  .logo-canvas {
    padding: 3rem; display: flex; align-items: center; justify-content: center;
    min-height: 240px; cursor: pointer; transition: opacity 0.2s;
  }
  .logo-canvas:hover { opacity: 0.85; }
  .logo-canvas-label {
    font-size: 0.65rem; font-weight: 600; letter-spacing: 0.12em;
    text-transform: uppercase; color: rgba(255,255,255,0.3);
    padding: 0.75rem 1.25rem; background: #23133a;
    border-top: 1px solid #3a1c63;
    text-align: center;
  }
  .logo-canvas-wrap { background: #23133a; }
  .logo-canvas-wrap.light { background: #f5f5f5; }
  .logo-canvas-wrap.color-bg { background: var(--ms-blue); }

  /* MS Logo SVG-style */
  .ms-logo-full { display: flex; align-items: center; gap: 18px; }
  .ms-symbol { display: grid; grid-template-columns: 1fr 1fr; gap: 3px; width: 46px; height: 46px; }
  .ms-symbol span { border-radius: 1px; }
  .ms-wordmark { font-family: var(--font-display); font-size: 1.6rem; font-weight: 600; letter-spacing: -0.01em; }
  .dark-text { color: #111; }

  .logo-rules {
    margin-top: 2rem;
    display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
  }
  .rule-card {
    background: #23133a; border-radius: 10px; padding: 1.25rem;
    border: 1px solid #3a1c63;
  }
  .rule-card-icon {
    width: 32px; height: 32px; border-radius: 6px;
    display: flex; align-items: center; justify-content: center;
    font-size: 1rem; margin-bottom: 10px;
  }
  .rule-card-title { font-size: 0.85rem; font-weight: 600; margin-bottom: 6px; }
  .rule-card-body { font-size: 0.78rem; color: rgba(255,255,255,0.45); line-height: 1.6; }
  .rule-do { border-top: 2px solid var(--ms-green); }
  .rule-dont { border-top: 2px solid #3a1c63; }
  .rule-note { border-top: 2px solid #3a1c63; }

  /* ─── TYPOGRAPHY SECTION ─── */
  #typography { background: #191127; }
  .type-showcase { margin-top: 3rem; }
  .type-specimen {
    border-radius: 12px; overflow: hidden; margin-bottom: 1px;
  }
  .type-row {
    display: grid; grid-template-columns: 180px 1fr; align-items: center;
    gap: 0; border-radius: 0; background: #23133a;
    border-bottom: 1px solid #3a1c63;
    transition: background 0.2s;
  }
  .type-row:hover { background: #1f1232; }
  .type-meta {
    padding: 1.25rem 1.5rem; border-right: 1px solid #3a1c63;
  }
  .type-meta-name { font-size: 0.7rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: rgba(255,255,255,0.35); margin-bottom: 3px; }
  .type-meta-size { font-family: var(--font-mono); font-size: 0.85rem; }
  .type-sample { padding: 1.25rem 2rem; font-size: 2.6rem; font-weight: 600; letter-spacing: -0.03em; overflow: hidden; white-space: nowrap; }
  .type-sample.light { font-weight: 300; }
  .type-sample.regular { font-weight: 400; font-size: 1.8rem; letter-spacing: -0.01em; }
  .type-sample.body { font-size: 1rem; font-weight: 400; letter-spacing: 0; line-height: 1.7; white-space: normal; }
  .type-sample.caption { font-size: 0.78rem; letter-spacing: 0.06em; text-transform: uppercase; font-weight: 500; }
  .type-sample.mono { font-family: var(--font-mono); font-size: 0.9rem; letter-spacing: 0; font-weight: 400; }
  .type-interactive {
    margin-top: 2rem; background: #23133a; border-radius: 12px; padding: 2rem;
  }
  .type-controls { display: flex; gap: 12px; margin-bottom: 1.5rem; flex-wrap: wrap; }
  .type-ctrl-btn {
    padding: 6px 14px; border-radius: 6px; font-size: 0.72rem;
    font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase;
    border: 1px solid #3a1c63; background: transparent;
    color: rgba(255,255,255,0.5); cursor: pointer; font-family: var(--font-display);
    transition: all 0.15s;
  }
  .type-ctrl-btn:hover, .type-ctrl-btn.active { background: white; color: #111; border-color: white; }
  .type-preview-text {
    font-size: clamp(2rem, 5vw, 4rem); font-weight: 700;
    letter-spacing: -0.03em; line-height: 1; transition: all 0.3s;
    min-height: 80px;
  }
  .type-size-slider { display: flex; align-items: center; gap: 16px; margin-top: 1rem; }
  .type-size-slider input { flex: 1; accent-color: var(--ms-blue); }
  .type-size-label { font-family: var(--font-mono); font-size: 0.8rem; color: rgba(255,255,255,0.4); min-width: 48px; }

  /* ─── VOICE SECTION ─── */
  #voice { background: #191127; }
  .voice-grid {
    margin-top: 3rem;
    display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px;
  }
  .voice-card {
    background: #23133a; border-radius: 12px; padding: 2rem;
    border: 1px solid #3a1c63;
    position: relative; overflow: hidden;
    transition: border-color 0.2s, transform 0.2s;
    cursor: default;
  }
  .voice-card:hover { border-color: #3a1c63; transform: translateY(-2px); }
  .voice-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  }
  .voice-card:nth-child(1)::before { background: var(--ms-blue); }
  .voice-card:nth-child(2)::before { background: var(--ms-green); }
  .voice-card:nth-child(3)::before { background: var(--ms-yellow); }
  .voice-card:nth-child(4)::before { background: var(--ms-red); }
  .voice-card-num {
    font-family: var(--font-mono); font-size: 0.65rem;
    color: rgba(255,255,255,0.2); margin-bottom: 12px;
  }
  .voice-card-title { font-size: 1.1rem; font-weight: 700; margin-bottom: 8px; }
  .voice-card-desc { font-size: 0.82rem; color: rgba(255,255,255,0.45); line-height: 1.65; margin-bottom: 1rem; }
  .voice-card-example {
    background: rgba(255,255,255,0.04); border-radius: 8px;
    padding: 1rem; border-left: 2px solid #3a1c63;
  }
  .voice-example-label { font-size: 0.6rem; letter-spacing: 0.12em; text-transform: uppercase; color: rgba(255,255,255,0.25); margin-bottom: 5px; }
  .voice-example-do { font-size: 0.82rem; color: rgba(255,255,255,0.7); margin-bottom: 4px; }
  .voice-example-dont { font-size: 0.82rem; color: rgba(255,255,255,0.25); text-decoration: line-through; }
  .do-tag { color: var(--ms-green); font-weight: 600; }
  .dont-tag { color: var(--ms-red); font-weight: 600; }

  /* ─── GUIDELINES SECTION ─── */
  #guidelines { background: #191127; }
  .guide-tabs { display: flex; gap: 0; margin-top: 2.5rem; margin-bottom: 0; border-bottom: 1px solid #3a1c63; }
  .guide-tab {
    padding: 10px 22px; font-size: 0.76rem; font-weight: 600;
    letter-spacing: 0.06em; text-transform: uppercase;
    color: rgba(255,255,255,0.3); cursor: pointer;
    border-bottom: 2px solid transparent; transition: all 0.2s;
    background: none; border-top: none; border-left: none; border-right: none;
    font-family: var(--font-display); margin-bottom: -1px;
  }
  .guide-tab.active, .guide-tab:hover { color: white; }
  .guide-tab.active { border-bottom-color: white; }
  .guide-panel { display: none; padding-top: 2rem; }
  .guide-panel.active { display: block; }
  .guide-items { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; background: rgba(255,255,255,0.05); border-radius: 12px; overflow: hidden; margin-top: 0; }
  .guide-item {
    background: #23133a; padding: 1.5rem; display: flex; gap: 14px; align-items: flex-start;
    transition: background 0.15s;
  }
  .guide-item:hover { background: #23133a; }
  .guide-item-icon {
    width: 34px; height: 34px; border-radius: 7px;
    flex-shrink: 0; display: flex; align-items: center; justify-content: center;
    font-size: 0.9rem;
  }

  .guide-item-title { font-size: 0.88rem; font-weight: 600; margin-bottom: 4px; }
  .guide-item-desc { font-size: 0.76rem; color: rgba(255,255,255,0.4); line-height: 1.6; }

  /* ─── QUIZ SECTION ─── */
  #quiz { background: #191127; }
  .quiz-container {
    margin-top: 3rem; max-width: 680px;
  }
  .quiz-q {
    font-size: 1.1rem; font-weight: 600; margin-bottom: 1.5rem;
    line-height: 1.45;
  }
  .quiz-q-num {
    font-family: var(--font-mono); font-size: 0.7rem;
    color: rgba(255,255,255,0.3); margin-bottom: 8px;
  }
  .quiz-options { display: flex; flex-direction: column; gap: 10px; margin-bottom: 1.5rem; }
  .quiz-option {
    padding: 1rem 1.25rem; border-radius: 10px;
    border: 1px solid #3a1c63;
    background: #23133a; cursor: pointer;
    font-size: 0.88rem; text-align: left; font-family: var(--font-display);
    color: rgba(255,255,255,0.7);
    transition: border-color 0.15s, background 0.15s;
  }
  .quiz-option:hover { border-color: #3a1c63; background: #1f1232; color: white; }
  .quiz-option.correct { border-color: #77b255; background: rgba(127,186,0,0.1); color: #60c090; }
  .quiz-option.wrong { border-color: #dc143c; background: rgba(242,80,34,0.1); color: #ff7a90; }
  .quiz-option.disabled { pointer-events: none; }
  .quiz-feedback {
    padding: 1rem 1.25rem; border-radius: 10px; font-size: 0.85rem;
    line-height: 1.6; margin-bottom: 1.5rem; display: none;
  }
  .quiz-feedback.show { display: block; }
  .quiz-feedback.correct { background: rgba(127,186,0,0.1); border: 1px solid #77b255; color: #60c090; }
  .quiz-feedback.wrong { background: rgba(242,80,34,0.08); border: 1px solid #dc143c; color: #ff7a90; }
  .quiz-btn {
    padding: 12px 28px; border-radius: 8px; font-size: 0.82rem; font-weight: 700;
    letter-spacing: 0.06em; text-transform: uppercase; cursor: pointer;
    font-family: var(--font-display); border: none; transition: transform 0.15s, opacity 0.15s;
  }
  .quiz-btn:hover { transform: translateY(-1px); opacity: 0.88; }
  .quiz-btn-next { background: var(--ms-blue); color: white; display: none; }
  .quiz-btn-next.show { display: inline-flex; }
  .quiz-progress {
    display: flex; gap: 6px; margin-bottom: 2rem;
  }
  .quiz-dot { width: 28px; height: 3px; border-radius: 2px; background: rgba(255,255,255,0.12); transition: background 0.3s; }
  .quiz-dot.done { background: white; }
  .quiz-dot.current { background: var(--ms-blue); }
  .quiz-score-wrap {
    text-align: center; padding: 3rem; background: #23133a;
    border-radius: 16px; display: none;
  }
  .quiz-score-wrap.show { display: block; }
  .quiz-score-num {
    font-size: 5rem; font-weight: 800; letter-spacing: -0.04em;
    line-height: 1; margin-bottom: 0.5rem;
  }
  .quiz-score-label { font-size: 0.9rem; color: rgba(255,255,255,0.4); margin-bottom: 2rem; }

  /* ─── FOOTER ─── */
  footer {
    padding: 3rem 2.5rem; border-top: 1px solid #3a1c63;
    display: flex; align-items: center; justify-content: space-between;
    flex-wrap: wrap; gap: 1rem;
  }
  .footer-logo { font-size: 0.9rem; font-weight: 700; display: flex; align-items: center; gap: 10px; }
  .footer-note { font-size: 0.72rem; color: rgba(255,255,255,0.25); }

  /* ─── UTILS ─── */
  .copied-toast {
    position: fixed; bottom: 2rem; right: 2rem;
    background: white; color: #111;
    padding: 10px 20px; border-radius: 8px;
    font-size: 0.8rem; font-weight: 600;
    opacity: 0; transform: translateY(10px);
    transition: all 0.25s; z-index: 999; pointer-events: none;
  }
  .copied-toast.show { opacity: 1; transform: translateY(0); }

  @media (max-width: 760px) {
    nav { padding: 0 1.25rem; }
    .nav-links { display: none; }
    section { padding: 4rem 1.25rem; }
    .hero { padding-left: 1.25rem; padding-right: 1.25rem; }
    .colors-grid { grid-template-columns: repeat(3, 1fr); }
    .logo-demo { grid-template-columns: 1fr; }
    .voice-grid { grid-template-columns: 1fr; }
    .logo-rules, .guide-items { grid-template-columns: 1fr; }
    footer { flex-direction: column; gap: 0.5rem; }
  }