/* ═══════════════════════════════════════════════════════════════
   IR TELECOMMUNICATION · S&T KNOWLEDGE HUB
   Design system — main.css
   Light theme is default. Dark theme is opt-in via [data-theme="dark"].
═══════════════════════════════════════════════════════════════ */

/* ── FONTS ── */
/* Display/body: Inter. Data/code/labels: Space Mono (kept as --ffm / --ff-mono,
   both names supported so legacy topic markup keeps working). */

:root {
  /* ---- Brand ---- */
  --blue:        #1d5fb4;
  --blue-light:  #4d82d6;
  --blue-bg:     rgba(29,95,180,0.07);
  --green:       #0e8f4f;
  --green-d:     #0a7a42;
  --green-bg:    rgba(14,143,79,0.08);
  --amber:       #b3760a;
  --amber-bg:    rgba(179,118,10,0.10);
  --red:         #c23636;
  --red-bg:      rgba(194,54,54,0.08);

  /* ---- Surfaces (LIGHT — default) ---- */
  --bg:          #f6f7f9;
  --bg2:         #ffffff;
  --bg3:         #eef1f5;
  --surface:     #ffffff;
  --surface2:    #f3f5f8;
  --card-bg:     #ffffff;
  --border:      #e3e7ed;
  --border2:     #d3d9e2;

  /* ---- Text ---- */
  --text:        #1a2233;
  --text2:       #5b6678;
  --text3:       #8b94a3;

  /* ---- Type ---- */
  --ff:          'Inter', system-ui, -apple-system, sans-serif;
  --ffm:         'Space Mono', monospace;
  --ff-display:  'Inter', system-ui, sans-serif;
  --ff-mono:     'Space Mono', monospace;

  /* ---- Misc ---- */
  --r:           8px;
  --r2:          14px;
  --tr:          0.18s ease;
  --shadow-sm:   0 1px 2px rgba(20,30,50,0.04), 0 1px 1px rgba(20,30,50,0.03);
  --shadow-md:   0 6px 20px rgba(20,30,50,0.07), 0 2px 6px rgba(20,30,50,0.05);
  --shadow-lg:   0 16px 40px rgba(20,30,50,0.12), 0 4px 12px rgba(20,30,50,0.06);
}

/* ---- DARK THEME (opt-in) ---- */
[data-theme="dark"] {
  --blue:        #5b8dee;
  --blue-light:  #82a8f0;
  --blue-bg:     rgba(91,141,238,0.10);
  --green:       #1fce7a;
  --green-d:     #16b568;
  --green-bg:    rgba(31,206,122,0.09);
  --amber:       #ffab1f;
  --amber-bg:    rgba(255,171,31,0.10);
  --red:         #ff5a5a;
  --red-bg:      rgba(255,90,90,0.09);

  --bg:          #0b1120;
  --bg2:         #111928;
  --bg3:         #1a2438;
  --surface:     #141d30;
  --surface2:    #1a2438;
  --card-bg:     #131c2e;
  --border:      #232f47;
  --border2:     #2c3a55;

  --text:        #e8edf5;
  --text2:       #9aabc4;
  --text3:       #5c6c87;

  --shadow-sm:   0 1px 2px rgba(0,0,0,0.3);
  --shadow-md:   0 6px 20px rgba(0,0,0,0.35);
  --shadow-lg:   0 20px 50px rgba(0,0,0,0.5);
}

/* ── RESET ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  background: var(--bg); color: var(--text); font-family: var(--ff);
  font-size: 15px; line-height: 1.6; overflow-x: hidden;
  transition: background 0.25s, color 0.25s;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font-family: inherit; }

.container { max-width: 1120px; margin: 0 auto; padding: 0 20px; }
.container-narrow { max-width: 760px; margin: 0 auto; padding: 0 20px; }

/* Respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

/* Visible keyboard focus */
a:focus-visible, button:focus-visible, input:focus-visible {
  outline: 2px solid var(--blue); outline-offset: 2px; border-radius: 4px;
}

/* ══════════════════════════════════════════
   NAVBAR
══════════════════════════════════════════ */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 300;
  background: rgba(246,247,249,0.92);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow 0.2s, background 0.25s;
}
[data-theme="dark"] .nav { background: rgba(11,17,32,0.92); }

.nav-inner {
  max-width: 1120px; margin: 0 auto; padding: 0 20px;
  height: 60px; display: flex; align-items: center; gap: 18px;
}

/* Logo */
.nav-logo { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.nav-logo-emblem {
  width: 34px; height: 34px; border-radius: 8px;
  background: var(--blue); display: flex; align-items: center; justify-content: center; overflow: hidden;
  flex-shrink: 0;
}
.nav-logo-img { width: 30px; height: 30px; object-fit: contain; }
.nav-logo-fallback {
  font-family: var(--ffm); font-weight: 700; font-size: 12px;
  color: #fff; display: flex; align-items: center; justify-content: center; width: 100%; height: 100%;
}
.nav-logo-text { display: flex; flex-direction: column; gap: 0; line-height: 1.15; }
.nav-logo-title { font-size: 13.5px; font-weight: 700; color: var(--text); letter-spacing: -0.2px; }
.nav-logo-sub { font-size: 10px; color: var(--text3); font-family: var(--ffm); letter-spacing: 0.4px; }

/* Desktop center links */
.nav-center { display: flex; align-items: center; gap: 2px; margin-left: 8px; }
.nav-link {
  font-size: 13px; font-weight: 500; color: var(--text2); padding: 7px 13px;
  border-radius: 7px; transition: all var(--tr); white-space: nowrap;
}
.nav-link:hover { color: var(--text); background: var(--surface2); }
.nav-link.active { color: var(--blue); background: var(--blue-bg); }

/* Desktop right */
.nav-right { display: flex; align-items: center; gap: 10px; margin-left: auto; }

.nav-clock-block {
  display: flex; flex-direction: column; align-items: flex-end; gap: 1px;
  padding: 5px 12px; background: var(--surface2); border: 1px solid var(--border);
  border-radius: 8px; min-width: 92px;
}
.nav-clock-time { font-family: var(--ffm); font-size: 13px; font-weight: 700; color: var(--green); letter-spacing: 0.5px; }
.nav-clock-date { font-family: var(--ffm); font-size: 9px; color: var(--text3); letter-spacing: 0.3px; }

.theme-toggle {
  width: 36px; height: 36px; border-radius: 8px; border: 1px solid var(--border2);
  background: var(--surface); cursor: pointer; display: flex; align-items: center;
  justify-content: center; font-size: 15px; transition: all var(--tr); flex-shrink: 0;
}
.theme-toggle:hover { background: var(--surface2); border-color: var(--text3); }

.nav-cta-btn {
  font-size: 12.5px; font-weight: 600; color: #fff; background: var(--blue);
  padding: 9px 16px; border-radius: 8px; transition: all var(--tr); white-space: nowrap;
}
.nav-cta-btn:hover { background: var(--blue-light); }

/* Mobile right (visible on mobile only) */
.nav-mobile-right { display: none; align-items: center; gap: 10px; margin-left: auto; }
.nav-mobile-clock-inline {
  display: none; flex-direction: column; align-items: flex-end; line-height: 1.15; gap: 0;
}
.nav-mobile-clock-inline .nmc-time { font-family: var(--ffm); font-size: 12px; font-weight: 700; color: var(--green); }
.nav-mobile-clock-inline .nmc-date { font-family: var(--ffm); font-size: 8px; color: var(--text3); }

.nav-burger {
  display: flex; flex-direction: column; gap: 5px; background: none; border: none;
  cursor: pointer; padding: 6px; border-radius: 6px; justify-content: center;
}
.nav-burger span { display: block; width: 20px; height: 2px; background: var(--text); border-radius: 2px; transition: all var(--tr); }
.nav-burger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-burger.open span:nth-child(2) { opacity: 0; }
.nav-burger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Drawer */
.nav-drawer {
  display: none; flex-direction: column; background: var(--bg2);
  border-top: 1px solid var(--border); overflow: hidden;
}
.nav-drawer.open { display: flex; }
.drawer-link {
  padding: 14px 20px; color: var(--text2); font-size: 14px;
  border-bottom: 1px solid var(--border); transition: all var(--tr);
  display: flex; align-items: center; gap: 8px;
}
.drawer-link:hover { color: var(--text); background: var(--surface2); }
.drawer-cta { color: var(--green); font-weight: 600; }
.drawer-cta:hover { background: var(--green-bg); }
.drawer-clock {
  padding: 12px 20px; display: flex; align-items: center; gap: 8px;
  font-family: var(--ffm); font-size: 12px; color: var(--text2);
  border-bottom: 1px solid var(--border); background: var(--surface2);
}
.drawer-clock .dc-time { color: var(--green); font-weight: 700; font-size: 14px; }

/* ══════════════════════════════════════════
   PAGE HERO (shared lightweight header used on
   topics/syllabus/about/phase pages)
══════════════════════════════════════════ */
.page-hero {
  padding: 124px 0 40px; background: var(--bg2); border-bottom: 1px solid var(--border);
}
.breadcrumb { display: flex; align-items: center; gap: 8px; font-size: 12.5px; color: var(--text3); margin-bottom: 18px; flex-wrap: wrap; }
.breadcrumb a { color: var(--text3); transition: color var(--tr); }
.breadcrumb a:hover { color: var(--blue); }
.breadcrumb .sep { color: var(--border2); }
.breadcrumb .cur { color: var(--text2); font-weight: 600; }

.page-eyebrow {
  font-family: var(--ffm); font-size: 11px; color: var(--green-d); letter-spacing: 2.5px;
  text-transform: uppercase; display: inline-flex; align-items: center; gap: 8px; margin-bottom: 14px;
}
.page-eyebrow::before { content: ''; width: 18px; height: 1px; background: var(--green-d); }
.page-title { font-size: clamp(26px, 4vw, 40px); font-weight: 700; letter-spacing: -1px; color: var(--text); line-height: 1.15; margin-bottom: 12px; }
.page-sub { font-size: 14.5px; color: var(--text2); line-height: 1.7; max-width: 620px; }

.page-meta-row { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 18px; }
.mpill {
  font-family: var(--ffm); font-size: 10px; font-weight: 700; padding: 4px 11px;
  border-radius: 100px; letter-spacing: 0.5px; border: 1px solid;
}
.mp-green { background: var(--green-bg); color: var(--green-d); border-color: rgba(14,143,79,0.25); }
[data-theme="dark"] .mp-green { color: var(--green); }
.mp-blue  { background: var(--blue-bg);  color: var(--blue);   border-color: rgba(29,95,180,0.25); }
.mp-amber { background: var(--amber-bg); color: var(--amber);  border-color: rgba(179,118,10,0.25); }

/* ══════════════════════════════════════════
   HOME · HERO BANNER  (single, focused — no slider)
══════════════════════════════════════════ */
.home-hero {
  position: relative; margin-top: 60px; overflow: hidden;
  background: linear-gradient(150deg, #0b1a35 0%, #0d2a55 45%, #0b3a52 100%);
}
.home-hero::before {
  content: ''; position: absolute; inset: 0;
  background-image:
    radial-gradient(circle at 18% 30%, rgba(29,95,180,0.35) 0%, transparent 45%),
    radial-gradient(circle at 82% 75%, rgba(14,143,79,0.18) 0%, transparent 45%);
}
.home-hero-inner {
  position: relative; z-index: 2; padding: 88px 20px 56px; max-width: 1120px; margin: 0 auto;
}
.hh-eyebrow {
  font-family: var(--ffm); font-size: 11px; color: #5fe39a; letter-spacing: 2.5px;
  text-transform: uppercase; display: inline-flex; align-items: center; gap: 8px; margin-bottom: 18px;
}
.hh-eyebrow::before { content: ''; width: 20px; height: 1px; background: #5fe39a; }
.hh-title {
  font-size: clamp(30px, 5.4vw, 54px); font-weight: 700; line-height: 1.1;
  letter-spacing: -1.5px; color: #fff; margin-bottom: 16px; max-width: 760px;
}
.hh-accent {
  background: linear-gradient(90deg, #34d281, #5b8dee);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.hh-desc {
  font-size: clamp(13.5px, 1.6vw, 16px); color: rgba(255,255,255,0.72);
  max-width: 540px; line-height: 1.7; margin-bottom: 28px;
}
.hh-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 40px; }
.hh-btn-primary {
  background: #1fce7a; color: #08291a; font-weight: 700; font-size: 13.5px;
  padding: 12px 24px; border-radius: 9px; transition: all var(--tr);
}
.hh-btn-primary:hover { background: #34d281; transform: translateY(-1px); }
.hh-btn-ghost {
  color: rgba(255,255,255,0.85); font-size: 13.5px; font-weight: 500;
  padding: 12px 20px; border: 1px solid rgba(255,255,255,0.25); border-radius: 9px;
  transition: all var(--tr);
}
.hh-btn-ghost:hover { border-color: rgba(255,255,255,0.5); color: #fff; background: rgba(255,255,255,0.06); }

.hh-stats {
  display: flex; flex-wrap: wrap; gap: 0;
  background: rgba(255,255,255,0.06); backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,0.1); border-radius: 12px;
  padding: 4px;
}
.hhs-item { flex: 1; min-width: 110px; display: flex; flex-direction: column; align-items: center; padding: 14px 12px; gap: 3px; }
.hhs-num { font-family: var(--ffm); font-size: 19px; font-weight: 700; color: #5fe39a; }
.hhs-lbl { font-size: 10px; color: rgba(255,255,255,0.55); letter-spacing: 1px; text-transform: uppercase; }
.hhs-div { width: 1px; background: rgba(255,255,255,0.1); margin: 10px 0; }

/* ══════════════════════════════════════════
   HOME · SUMMARY (CSRIP-style) CARDS
══════════════════════════════════════════ */
.summary-section { padding: 64px 0 56px; }
.section-header { margin-bottom: 36px; max-width: 640px; }
.section-eyebrow {
  font-family: var(--ffm); font-size: 10.5px; color: var(--green-d); letter-spacing: 2.5px;
  text-transform: uppercase; display: block; margin-bottom: 10px;
}
.section-title { font-size: clamp(22px, 3.2vw, 32px); font-weight: 700; letter-spacing: -0.8px; color: var(--text); line-height: 1.2; margin-bottom: 8px; }
.section-sub { font-size: 13.5px; color: var(--text2); line-height: 1.7; }

.summary-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin-bottom: 16px; }
.summary-card {
  background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--r2);
  padding: 22px; display: flex; flex-direction: column; gap: 6px;
  transition: all var(--tr);
}
.summary-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); border-color: var(--border2); }
.sc-icon { font-size: 22px; margin-bottom: 4px; }
.sc-num { font-family: var(--ffm); font-size: 24px; font-weight: 700; color: var(--text); letter-spacing: -0.5px; }
.sc-lbl { font-size: 12.5px; color: var(--text2); font-weight: 500; }

/* Live-now strip on homepage */
.live-strip {
  background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--r2);
  padding: 6px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px;
}
.live-link {
  display: flex; align-items: center; gap: 12px; padding: 14px 16px; border-radius: 10px;
  transition: all var(--tr);
}
.live-link:hover { background: var(--surface2); }
.live-link-icon { font-size: 20px; flex-shrink: 0; }
.live-link-text { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.live-link-title { font-size: 13px; font-weight: 600; color: var(--text); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.live-link-code { font-family: var(--ffm); font-size: 10px; color: var(--green-d); letter-spacing: 0.5px; }

/* Explore tiles: Phase I / Phase II / Syllabus / About */
.explore-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.explore-tile {
  background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--r2);
  padding: 24px; display: flex; flex-direction: column; gap: 10px; transition: all var(--tr);
  position: relative; overflow: hidden;
}
.explore-tile:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); border-color: var(--border2); }
.et-icon {
  width: 38px; height: 38px; border-radius: 10px; display: flex; align-items: center;
  justify-content: center; font-size: 18px; flex-shrink: 0;
}
.et-icon.p1 { background: var(--blue-bg); }
.et-icon.p2 { background: var(--green-bg); }
.et-icon.syl { background: var(--amber-bg); }
.et-icon.abt { background: var(--surface2); }
.et-title { font-size: 15px; font-weight: 700; color: var(--text); letter-spacing: -0.2px; }
.et-desc { font-size: 12.5px; color: var(--text2); line-height: 1.6; flex: 1; }
.et-arrow { font-family: var(--ffm); font-size: 12px; color: var(--text3); transition: all var(--tr); }
.explore-tile:hover .et-arrow { color: var(--blue); transform: translateX(3px); }

/* ══════════════════════════════════════════
   STATS BAR (compact info row)
══════════════════════════════════════════ */
.stats-bar { background: var(--bg2); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.stats-bar-inner { display: flex; align-items: center; flex-wrap: wrap; min-height: 54px; }
.sbar-item { display: flex; align-items: center; gap: 10px; padding: 12px 20px; flex: 1; min-width: 160px; }
.sbar-icon { font-size: 17px; flex-shrink: 0; }
.sbar-val { display: block; font-size: 13px; font-weight: 600; color: var(--text); line-height: 1.2; }
.sbar-lbl { display: block; font-size: 10px; color: var(--text3); letter-spacing: 0.4px; }
.sbar-div { width: 1px; height: 30px; background: var(--border); }
.live-dot-text { color: var(--green-d); }
[data-theme="dark"] .live-dot-text { color: var(--green); }

/* ══════════════════════════════════════════
   SYLLABUS / PHASE PAGES
══════════════════════════════════════════ */
.syllabus-section { padding: 56px 0 80px; }

.phase-block { margin-bottom: 56px; }
.phase-label-row {
  display: flex; align-items: center; gap: 14px; margin-bottom: 24px;
  flex-wrap: wrap; padding-bottom: 16px; border-bottom: 1px solid var(--border);
}
.phase-pill {
  font-family: var(--ffm); font-size: 10px; font-weight: 700;
  padding: 4px 12px; border-radius: 100px; letter-spacing: 1.2px;
}
.p1 { background: var(--blue-bg); color: var(--blue); border: 1px solid rgba(29,95,180,0.22); }
.p2 { background: var(--green-bg); color: var(--green-d); border: 1px solid rgba(14,143,79,0.22); }
[data-theme="dark"] .p2 { color: var(--green); }
.phase-name { font-size: 17px; font-weight: 600; color: var(--text); letter-spacing: -0.3px; }
.phase-meta { font-family: var(--ffm); font-size: 11px; color: var(--text3); margin-left: auto; }

.cards-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 16px; }

.scard {
  background: var(--card-bg); border: 1px solid var(--border);
  border-radius: var(--r2); padding: 20px;
  display: flex; flex-direction: column; gap: 10px;
  transition: all var(--tr); position: relative;
}
.scard:not(.live) { opacity: 0.7; }
.scard:not(.live):hover { opacity: 0.92; }
.scard.live { border-color: rgba(14,143,79,0.35); box-shadow: 0 0 0 1px rgba(14,143,79,0.08); }
.scard.live:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); border-color: rgba(14,143,79,0.5); }

.scard-header { display: flex; justify-content: space-between; align-items: center; }
.scard-code { font-family: var(--ffm); font-size: 10px; color: var(--text3); letter-spacing: 1.2px; }
.scard-badge { font-family: var(--ffm); font-size: 8px; font-weight: 700; padding: 2px 8px; border-radius: 100px; letter-spacing: 0.4px; }
.scard-badge.live { background: var(--green-bg); color: var(--green-d); border: 1px solid rgba(14,143,79,0.3); }
[data-theme="dark"] .scard-badge.live { color: var(--green); }
.scard-badge.soon { background: var(--amber-bg); color: var(--amber); border: 1px solid rgba(179,118,10,0.3); }
.scard-icon { font-size: 22px; }
.scard-title { font-size: 14px; font-weight: 600; color: var(--text); line-height: 1.3; }
.scard-desc { font-size: 12px; color: var(--text2); line-height: 1.6; flex: 1; }

.scard-progress { display: flex; flex-direction: column; gap: 6px; margin-top: 4px; }
.prog-row { display: flex; align-items: center; gap: 8px; text-decoration: none; color: inherit; border-radius: 6px; padding: 2px 4px; transition: background var(--tr); }
.prog-row.clickable:hover { background: var(--surface2); }
.prog-label { font-family: var(--ffm); font-size: 10px; color: var(--text2); width: 64px; flex-shrink: 0; white-space: nowrap; }
.prog-label.muted { color: var(--text3); }
.prog-track { flex: 1; height: 5px; background: var(--border2); border-radius: 3px; overflow: hidden; }
.prog-fill { height: 100%; border-radius: 3px; transition: width 0.8s ease; }
.prog-fill.theory { background: linear-gradient(90deg, var(--blue), var(--blue-light)); }
.prog-fill.field { background: linear-gradient(90deg, var(--green-d), var(--green)); }
.prog-pct { font-family: var(--ffm); font-size: 10px; color: var(--text3); width: 28px; text-align: right; flex-shrink: 0; }
.prog-pct.muted { color: var(--border2); }

.phase-nav-strip {
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
  margin-top: 48px; padding: 22px 26px; background: var(--card-bg); border: 1px solid var(--border);
  border-radius: var(--r2); flex-wrap: wrap;
}
.pns-btn {
  font-size: 13px; font-weight: 600; color: var(--text2); padding: 10px 18px;
  border-radius: 9px; border: 1px solid var(--border2); transition: all var(--tr);
}
.pns-btn:hover { color: var(--text); border-color: var(--text3); background: var(--surface2); }
.pns-btn.primary { color: var(--green-d); border-color: rgba(14,143,79,0.3); background: var(--green-bg); }
[data-theme="dark"] .pns-btn.primary { color: var(--green); }

/* ══════════════════════════════════════════
   ABOUT PAGE
══════════════════════════════════════════ */
.about-section { padding: 56px 0 72px; }
.about-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 56px; align-items: start; }
.about-text { min-width: 0; }
.about-card-wrap { min-width: 0; }
.about-desc { font-size: 14px; color: var(--text2); line-height: 1.8; margin: 16px 0 24px; }
.about-features { display: flex; flex-direction: column; gap: 12px; }
.af-item { display: flex; align-items: flex-start; gap: 12px; font-size: 13px; color: var(--text2); line-height: 1.6; }
.af-icon { font-size: 16px; flex-shrink: 0; }

.about-stat-card { background: var(--surface); border: 1px solid var(--border2); border-radius: var(--r2); overflow: hidden; }
.asc-row { display: flex; justify-content: space-between; align-items: center; padding: 15px 20px; border-bottom: 1px solid var(--border); gap: 12px; }
.asc-row:last-child { border-bottom: none; }
.asc-row.highlight { background: var(--green-bg); }
.asc-label { font-size: 13px; color: var(--text2); }
.asc-val { font-family: var(--ffm); font-size: 13px; font-weight: 700; color: var(--text); text-align: right; }
.asc-val.green { color: var(--green-d); }
[data-theme="dark"] .asc-val.green { color: var(--green); }

.about-source {
  margin-top: 28px; padding: 16px 18px; background: var(--surface2); border: 1px solid var(--border);
  border-radius: var(--r); font-size: 12px; color: var(--text3); line-height: 1.7;
}
.about-source strong { color: var(--text2); }

/* ══════════════════════════════════════════
   FOOTER
══════════════════════════════════════════ */
.footer { padding: 36px 0 20px; background: var(--bg2); border-top: 1px solid var(--border); }
.footer-top, .footer-inner {
  display: flex; justify-content: space-between; align-items: center;
  padding-bottom: 20px; border-bottom: 1px solid var(--border);
  margin-bottom: 16px; flex-wrap: wrap; gap: 16px;
}
.footer-brand { display: flex; align-items: center; gap: 12px; }
.footer-logo, .ir-logo-img { width: 34px; height: 34px; object-fit: contain; }
.footer-title, .logo-text { font-size: 15px; font-weight: 700; color: var(--text); }
.footer-subtitle, .footer-tagline { font-size: 11px; color: var(--text3); font-family: var(--ffm); margin-top: 1px; }
.footer-badges, .footer-pills { display: flex; gap: 8px; flex-wrap: wrap; }
.fbadge, .fpill {
  font-family: var(--ffm); font-size: 9px; padding: 3px 9px;
  background: var(--surface); border: 1px solid var(--border2);
  border-radius: 4px; color: var(--text3); letter-spacing: 0.8px;
}
.footer-bottom { display: flex; justify-content: space-between; font-size: 11px; color: var(--text3); font-family: var(--ffm); flex-wrap: wrap; gap: 8px; }
.footer-ver { color: var(--green-d); }
[data-theme="dark"] .footer-ver { color: var(--green); }

/* ══════════════════════════════════════════
   TOPIC PAGE LAYOUT (theory/field content pages)
══════════════════════════════════════════ */
.topic-body-wrap { padding-top: 60px; }
.topic-body { padding: 40px 0 60px; }
.topic-layout { display: grid; grid-template-columns: 220px 1fr; gap: 48px; align-items: start; }

.toc { position: sticky; top: 84px; }
.toc-head { font-family: var(--ffm); font-size: 9px; color: var(--text3); letter-spacing: 2px; text-transform: uppercase; margin-bottom: 10px; padding-bottom: 8px; border-bottom: 1px solid var(--border); }
.toc ul { list-style: none; display: flex; flex-direction: column; gap: 2px; }
.toc a {
  display: block; font-size: 12.5px; color: var(--text2); padding: 7px 10px; border-radius: 7px;
  transition: all var(--tr); line-height: 1.4;
}
.toc a:hover { color: var(--text); background: var(--surface2); }
.toc a.toc-active { color: var(--blue); background: var(--blue-bg); font-weight: 600; }

.content { min-width: 0; }
.content h2 {
  font-family: var(--ff-display); font-size: 21px; font-weight: 800; letter-spacing: -0.5px;
  color: var(--text); margin: 48px 0 16px; display: flex; align-items: center; gap: 12px;
  border-bottom: 1px solid var(--border); padding-bottom: 10px;
}
.content h2:first-of-type { margin-top: 0; }
.content h3 { font-family: var(--ff-display); font-size: 14.5px; font-weight: 700; color: var(--text2); letter-spacing: -0.2px; margin: 26px 0 10px; }
.content p { font-size: 13.5px; color: var(--text2); line-height: 1.8; margin-bottom: 14px; }
.content p strong, .content li strong, .content div strong { color: var(--text); }
.h2n {
  font-family: var(--ff-mono); font-size: 10.5px; color: var(--green-d); background: var(--green-bg);
  border: 1px solid rgba(14,143,79,0.2); padding: 3px 8px; border-radius: 5px; flex-shrink: 0;
}
[data-theme="dark"] .h2n { color: var(--green); }

/* Sticky section switcher (theory/field toggle) */
.section-switcher { position: sticky; top: 60px; z-index: 90; background: var(--bg); border-bottom: 1px solid var(--border); padding: 10px 0; }
.ss-inner { max-width: 900px; margin: 0 auto; padding: 0 24px; display: flex; align-items: center; gap: 0; background: var(--surface); border: 1px solid var(--border2); border-radius: 40px; width: fit-content; }
.ss-btn { display: flex; align-items: center; gap: 8px; padding: 9px 22px; border-radius: 40px; text-decoration: none; color: var(--text3); font-family: var(--ff-mono); font-size: 11px; letter-spacing: 0.5px; transition: all var(--tr); position: relative; }
.ss-btn:hover { color: var(--text); }
.ss-btn.active { color: var(--text); }
.ss-btn#ssBtnTheory.active { color: var(--blue); background: var(--blue-bg); }
.ss-btn#ssBtnField.active { color: var(--green-d); background: var(--green-bg); }
[data-theme="dark"] .ss-btn#ssBtnField.active { color: var(--green); }
.ss-icon { font-size: 13px; }
.ss-label { font-weight: 700; }
.ss-pct { font-size: 9px; color: inherit; opacity: 0.7; background: var(--bg3); border: 1px solid var(--border); padding: 1px 6px; border-radius: 8px; }
.ss-divider { width: 1px; height: 20px; background: var(--border2); }

/* Section banners */
.section-banner { display: flex; justify-content: space-between; align-items: center; gap: 16px; border-radius: var(--r2); padding: 18px 24px; margin: 0 0 28px; border: 1.5px solid; }
.theory-banner { background: var(--blue-bg); border-color: rgba(29,95,180,0.22); }
.field-banner { background: var(--green-bg); border-color: rgba(14,143,79,0.2); }
.sb-left { display: flex; align-items: center; gap: 14px; }
.sb-icon { font-size: 26px; flex-shrink: 0; }
.sb-tag { font-family: var(--ff-mono); font-size: 8px; letter-spacing: 3px; text-transform: uppercase; margin-bottom: 3px; }
.theory-banner .sb-tag { color: var(--blue); }
.field-banner .sb-tag { color: var(--green-d); }
[data-theme="dark"] .field-banner .sb-tag { color: var(--green); }
.sb-title { font-family: var(--ff-display); font-size: 15px; font-weight: 700; color: var(--text); letter-spacing: -0.3px; }
.sb-progress { display: flex; flex-direction: column; align-items: flex-end; gap: 5px; flex-shrink: 0; }
.sb-pct { font-family: var(--ff-mono); font-size: 18px; font-weight: 700; color: var(--text); }
.sb-track { width: 100px; height: 5px; background: var(--bg3); border-radius: 3px; overflow: hidden; border: 1px solid var(--border); }
.sb-fill { height: 100%; border-radius: 3px; }
.theory-fill { background: linear-gradient(90deg, var(--blue), var(--blue-light)); }
.field-fill { background: linear-gradient(90deg, var(--green-d), var(--green)); }

/* Info boxes */
.ibox { display: flex; gap: 14px; align-items: flex-start; background: var(--surface); border: 1px solid var(--border2); border-radius: var(--r); padding: 16px 18px; margin: 18px 0; }
.ibox.blue { background: var(--blue-bg); border-color: rgba(29,95,180,0.18); }
.ibox.amber { background: var(--amber-bg); border-color: rgba(179,118,10,0.2); }
.ibox.green { background: var(--green-bg); border-color: rgba(14,143,79,0.18); }
.ibox-icon { font-size: 20px; flex-shrink: 0; margin-top: 1px; }
.ibox-title { font-weight: 700; color: var(--text); font-size: 13px; margin-bottom: 4px; }
.ibox-text { font-size: 12px; color: var(--text2); line-height: 1.7; }
.ibox-text strong { color: var(--text); }

/* Flow / org chart cards */
.flow-card { background: var(--surface); border: 1px solid var(--border2); border-radius: var(--r2); padding: 20px; margin: 18px 0; }
.flow-label { font-family: var(--ff-mono); font-size: 8px; color: var(--text3); letter-spacing: 2px; text-transform: uppercase; margin-bottom: 18px; border-bottom: 1px solid var(--border); padding-bottom: 8px; }
.flow-chain { display: flex; flex-direction: column; align-items: center; gap: 6px; }
.flow-node { background: var(--bg3); border: 1px solid var(--border2); border-radius: 8px; padding: 10px 14px; text-align: center; width: 100%; }
.flow-node.top { background: linear-gradient(135deg, var(--green-bg), var(--bg3)); border-color: rgba(14,143,79,0.25); }
.flow-node.blue { background: var(--blue-bg); border-color: rgba(29,95,180,0.18); }
.fn-code { font-family: var(--ff-mono); font-size: 9px; color: var(--green-d); letter-spacing: 2px; margin-bottom: 3px; }
[data-theme="dark"] .fn-code { color: var(--green); }
.fn-title { font-size: 12px; font-weight: 700; color: var(--text); margin-bottom: 3px; }
.fn-sub { font-size: 10px; color: var(--text3); line-height: 1.5; }
.fn-sub strong { color: var(--amber); }
.flow-arrow { font-family: var(--ff-mono); font-size: 14px; color: var(--text3); }
.flow-row4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; width: 100%; }
.flow-row3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; width: 100%; }

/* Promotion chain */
.promo-chain { display: flex; align-items: center; gap: 6px; overflow-x: auto; padding: 4px 0; }
.pc-step { display: flex; flex-direction: column; align-items: center; gap: 4px; flex-shrink: 0; min-width: 80px; }
.pc-badge { font-family: var(--ff-mono); font-size: 7px; padding: 2px 6px; border-radius: 3px; letter-spacing: 0.3px; text-align: center; }
.pc-badge.new { background: var(--green-bg); color: var(--green-d); border: 1px solid rgba(14,143,79,0.2); }
[data-theme="dark"] .pc-badge.new { color: var(--green); }
.pc-badge.dept { background: var(--blue-bg); color: var(--blue); border: 1px solid rgba(29,95,180,0.18); }
.pc-badge.mid { background: var(--amber-bg); color: var(--amber); border: 1px solid rgba(179,118,10,0.2); }
.pc-title { font-family: var(--ff-mono); font-size: 10px; font-weight: 700; color: var(--text); text-align: center; }
.pc-sub { font-size: 8px; color: var(--text3); text-align: center; }
.pc-arrow { font-size: 16px; color: var(--border2); flex-shrink: 0; }

/* Hierarchy chain */
.hier-chain { display: flex; flex-direction: column; align-items: center; gap: 0; }
.hc-row { width: 100%; display: flex; justify-content: center; }
.hc-row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; width: 100%; }
.hc-row3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; width: 100%; }
.hc-connector { width: 1px; height: 16px; background: var(--border2); margin: 0 auto; }
.hc-node { background: var(--bg3); border: 1px solid var(--border2); border-radius: 8px; padding: 10px 14px; font-size: 11px; color: var(--text2); line-height: 1.5; text-align: center; width: 100%; }
.hc-node.top { background: linear-gradient(135deg, var(--green-bg), var(--bg3)); border-color: rgba(14,143,79,0.25); font-size: 12px; font-weight: 700; color: var(--text); }
.hc-node.highlight { border-color: rgba(179,118,10,0.3); background: var(--amber-bg); }
.hc-code { font-family: var(--ff-mono); font-size: 9px; color: var(--green-d); letter-spacing: 1px; margin-bottom: 4px; }
[data-theme="dark"] .hc-code { color: var(--green); }
.hc-sub { font-size: 10px; color: var(--text3); margin-top: 3px; }

/* Comparison tables */
.cmp-table-wrap { border: 1px solid var(--border); border-radius: var(--r2); overflow: hidden; margin: 14px 0; }
.cmp-table { width: 100%; border-collapse: collapse; }
.cmp-table th { background: var(--bg3); font-family: var(--ff-mono); font-size: 9px; color: var(--text3); letter-spacing: 1.2px; text-transform: uppercase; padding: 9px 12px; text-align: left; border-bottom: 1px solid var(--border); }
.cmp-table td { padding: 9px 12px; font-size: 12px; color: var(--text2); border-bottom: 1px solid var(--border); line-height: 1.6; vertical-align: top; }
.cmp-table tr:last-child td { border-bottom: none; }
.cmp-table tr:hover td { background: var(--surface2); }
.cmp-table tr.hl-row td { background: var(--green-bg); border-left: 3px solid rgba(14,143,79,0.3); }
.cmp-table td.mono { font-family: var(--ff-mono); font-size: 11px; color: var(--text); font-weight: 700; }
.cmp-table td strong { color: var(--text); }

.cat-i { color: var(--green-d) !important; }
[data-theme="dark"] .cat-i { color: var(--green) !important; }
.cat-c { color: var(--blue) !important; }
.cat-ei { color: var(--amber) !important; }
.cat-ex { color: var(--text3) !important; }
.hoer-table td { font-size: 11px; }

/* Formula box */
.formula-box { background: linear-gradient(135deg, rgba(29,95,180,0.06), var(--green-bg)); border: 1.5px solid rgba(29,95,180,0.18); border-radius: var(--r2); padding: 18px 22px; margin: 18px 0; }
.fb-label { font-family: var(--ff-mono); font-size: 8px; color: var(--blue); letter-spacing: 3px; text-transform: uppercase; margin-bottom: 12px; padding-bottom: 8px; border-bottom: 1px solid rgba(29,95,180,0.13); }
.fb-row { display: flex; align-items: baseline; gap: 12px; padding: 5px 0; border-bottom: 1px solid rgba(29,95,180,0.08); flex-wrap: wrap; }
.fb-row:last-child { border-bottom: none; }
.fb-cat { font-family: var(--ff-mono); font-size: 10px; color: var(--text3); min-width: 120px; flex-shrink: 0; }
.fb-eq { font-size: 13px; color: var(--text); font-weight: 500; }
.fb-eq strong { color: var(--green-d); }
[data-theme="dark"] .fb-eq strong { color: var(--green); }

/* Duty grid */
.duty-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 16px 0; }
.duty-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r); padding: 16px; display: flex; flex-direction: column; gap: 8px; }
.duty-head { font-family: var(--ff-mono); font-size: 10px; color: var(--green-d); letter-spacing: 1px; padding-bottom: 8px; border-bottom: 1px solid var(--border); }
[data-theme="dark"] .duty-head { color: var(--green); }
.duty-list { display: flex; flex-direction: column; gap: 5px; }
.dl-item { display: flex; align-items: flex-start; gap: 8px; font-size: 12px; color: var(--text2); line-height: 1.6; }
.dl-dot { width: 6px; height: 6px; border-radius: 50%; flex-shrink: 0; margin-top: 5px; }
.dl-dot.g { background: var(--green); }
.dl-dot.b { background: var(--blue); }
.dl-dot.a { background: var(--amber); }
.dl-item strong { color: var(--text); }

/* Two column DO/DON'T */
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 16px 0; }
.col-block { border: 1px solid var(--border); border-radius: var(--r); padding: 14px; display: flex; flex-direction: column; gap: 8px; }
.col-block.good { background: var(--green-bg); border-color: rgba(14,143,79,0.18); }
.col-block.bad { background: var(--red-bg); border-color: rgba(194,54,54,0.18); }
.col-head { font-family: var(--ff-mono); font-size: 9px; letter-spacing: 1.2px; font-weight: 700; padding-bottom: 8px; border-bottom: 1px solid var(--border); }
.col-block.good .col-head { color: var(--green-d); }
[data-theme="dark"] .col-block.good .col-head { color: var(--green); }
.col-block.bad .col-head { color: var(--red); }
.col-items { display: flex; flex-direction: column; gap: 4px; }
.col-items div { font-size: 11px; color: var(--text2); padding: 3px 0; border-bottom: 1px solid var(--border); line-height: 1.5; }
.col-items div:last-child { border-bottom: none; }

/* Mnemonic grid */
.mnemonic-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; margin: 16px 0; }
.mn-card { background: var(--surface2); border: 1px solid var(--border2); border-radius: var(--r); padding: 14px; }
.mn-tag { font-family: var(--ff-mono); font-size: 7px; color: var(--amber); letter-spacing: 2px; text-transform: uppercase; margin-bottom: 6px; }
.mn-title { font-size: 13px; font-weight: 700; color: var(--text); margin-bottom: 6px; letter-spacing: -0.2px; }
.mn-body { font-size: 11px; color: var(--text2); line-height: 1.7; }
.mn-hl { color: var(--green-d); font-weight: 700; }
[data-theme="dark"] .mn-hl { color: var(--green); }

/* Recap strip + block */
.recap-strip { background: var(--bg3); border: 1px solid var(--border); border-left: 3px solid var(--amber); border-radius: 6px; padding: 8px 14px; font-family: var(--ff-mono); font-size: 10px; color: var(--text3); margin: 10px 0; line-height: 1.6; }
.recap-strip strong { color: var(--amber); }

.recap-block { background: var(--surface); border: 1px solid var(--border2); border-radius: var(--r2); overflow: hidden; margin: 40px 0 20px; }
.rb-head { font-family: var(--ff-mono); font-size: 9px; color: var(--green-d); letter-spacing: 3px; padding: 12px 18px; background: var(--bg3); border-bottom: 1px solid var(--border); }
[data-theme="dark"] .rb-head { color: var(--green); }
.rb-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0; }
.rb-item { padding: 12px 16px; border-bottom: 1px solid var(--border); border-right: 1px solid var(--border); }
.rb-item:nth-child(even) { border-right: none; }
.rb-item:nth-last-child(-n+2) { border-bottom: none; }
.rb-q { font-size: 11px; color: var(--text3); margin-bottom: 4px; font-style: italic; }
.rb-a { font-size: 12px; color: var(--text); font-weight: 600; }

/* Key rule callout */
.key-rule { background: linear-gradient(135deg, var(--green-bg), rgba(14,143,79,0.02)); border: 1.5px solid rgba(14,143,79,0.2); border-radius: var(--r2); padding: 22px 26px; margin: 28px 0; display: flex; gap: 16px; align-items: flex-start; }
.kr-icon { font-size: 22px; flex-shrink: 0; }
.kr-title { font-family: var(--ff-display); font-size: 15px; font-weight: 700; color: var(--green-d); margin-bottom: 8px; letter-spacing: -0.2px; }
[data-theme="dark"] .kr-title { color: var(--green); }
.kr-body { font-size: 13px; color: var(--text2); line-height: 1.8; }
.kr-body .g { color: var(--green-d); font-weight: 600; }
[data-theme="dark"] .kr-body .g { color: var(--green); }
.kr-body .r { color: var(--red); font-weight: 600; }

/* Next strip / page nav */
.next-strip, .ns-pair { margin-top: 56px; padding: 26px 28px; background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--r2); display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; }
.ns-label { font-family: var(--ff-mono); font-size: 9px; color: var(--text3); letter-spacing: 2px; margin-bottom: 5px; }
.ns-title { font-family: var(--ff-display); font-size: 17px; font-weight: 700; color: var(--text2); letter-spacing: -0.3px; }
.ns-btn { font-family: var(--ff-mono); font-size: 11px; padding: 10px 20px; border-radius: 9px; border: 1px solid var(--border2); color: var(--text2); transition: all var(--tr); display: inline-flex; align-items: center; }
.ns-btn:hover { color: var(--text); border-color: var(--text3); background: var(--surface2); }
.ns-btn.home { color: var(--green-d); border-color: rgba(14,143,79,0.22); background: var(--green-bg); }
[data-theme="dark"] .ns-btn.home { color: var(--green); }
.ns-btn.home:hover { background: rgba(14,143,79,0.16); }
.ns-btn.next-field { color: var(--green-d); border-color: rgba(14,143,79,0.25); background: var(--green-bg); }
[data-theme="dark"] .ns-btn.next-field { color: var(--green); }

/* Device diagram (media converter style) */
.diag-card { background: var(--surface); border: 1px solid var(--border2); border-radius: var(--r2); padding: 24px; margin: 18px 0; }
.diag-label { font-family: var(--ff-mono); font-size: 9px; color: var(--text3); letter-spacing: 1.5px; text-transform: uppercase; margin-bottom: 20px; }
.device-diag { display: flex; align-items: center; gap: 0; flex-wrap: wrap; justify-content: center; padding: 12px 0; }
.dd-side { display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 14px 16px; border-radius: 10px; font-size: 10px; text-align: center; line-height: 1.5; min-width: 84px; }
.dd-side.fiber { background: var(--blue-bg); border: 1px solid rgba(29,95,180,0.22); }
.dd-side.copper { background: var(--amber-bg); border: 1px solid rgba(179,118,10,0.22); }
.dd-side-title { font-family: var(--ff-mono); font-weight: 700; font-size: 10px; letter-spacing: 1px; margin-bottom: 4px; color: var(--text); }
.dd-cables { display: flex; flex-direction: column; gap: 6px; padding: 0 8px; }
.dd-fline, .dd-ethline { width: 32px; height: 3px; border-radius: 2px; }
.dd-fline { background: var(--blue); }
.dd-ethline { background: var(--amber); }
.dd-scports, .dd-rj45 { display: flex; flex-direction: column; gap: 8px; padding: 0 4px; }
.dd-sc { width: 16px; height: 16px; border-radius: 4px; background: var(--blue); border: 2px solid var(--bg2); box-shadow: 0 0 0 1px var(--border2); }
.dd-rj45 { width: 20px; height: 14px; border-radius: 3px; background: var(--amber); border: 2px solid var(--bg2); box-shadow: 0 0 0 1px var(--border2); }
.dd-body { background: var(--bg3); border: 1.5px solid var(--border2); border-radius: 10px; padding: 16px 22px; display: flex; flex-direction: column; align-items: center; gap: 10px; min-width: 220px; }
.dd-brand { font-size: 11px; font-weight: 700; color: var(--text); letter-spacing: -0.2px; }
.dd-blabel { font-family: var(--ff-mono); font-size: 9px; color: var(--text3); letter-spacing: 0.5px; margin-bottom: 4px; }
.dd-leds { display: flex; gap: 14px; flex-wrap: wrap; justify-content: center; }
.dd-li { display: flex; flex-direction: column; align-items: center; gap: 5px; }
.dd-led { width: 11px; height: 11px; border-radius: 50%; background: var(--border2); }
.dd-led.on { background: var(--green); box-shadow: 0 0 8px rgba(14,143,79,0.5); }
.dd-led.off { background: var(--border2); }
.dd-led.blink { background: var(--green); box-shadow: 0 0 8px rgba(14,143,79,0.5); animation: ledblink 1.4s ease-in-out infinite; }
@keyframes ledblink { 0%, 45% { opacity: 1; } 50%, 95% { opacity: 0.25; } 100% { opacity: 1; } }
.dd-ll { font-family: var(--ff-mono); font-size: 8px; color: var(--text3); text-align: center; line-height: 1.3; }

/* LED reference table */
.led-wrap { display: flex; flex-direction: column; gap: 1px; border: 1px solid var(--border); border-radius: var(--r2); overflow: hidden; margin: 18px 0; }
.led-head, .led-row { display: grid; grid-template-columns: 22px 110px 1fr 150px 100px; gap: 12px; padding: 12px 16px; align-items: center; }
.led-head { background: var(--bg3); font-family: var(--ff-mono); font-size: 9px; color: var(--text3); letter-spacing: 1.2px; text-transform: uppercase; }
.led-th { white-space: nowrap; }
.led-row { background: var(--surface); border-top: 1px solid var(--border); }
.led-row.hl { background: var(--green-bg); }
.l-name { display: flex; flex-direction: column; gap: 1px; font-weight: 700; font-size: 12px; color: var(--text); }
.ldot { width: 9px; height: 9px; border-radius: 50%; flex-shrink: 0; }
.ldot.green { background: var(--green); }
.ldot.blink-ok { background: var(--green); animation: ledblink 1.4s ease-in-out infinite; }
.ldot.amber { background: var(--amber); }
.l-mean { font-size: 12px; color: var(--text2); }
.l-sub { font-size: 10.5px; color: var(--text3); margin-top: 2px; }
.l-state { font-size: 11.5px; color: var(--text2); display: flex; flex-direction: column; gap: 3px; }
.l-state.stable-bad { color: var(--red); font-weight: 600; }
.blink-ok { color: var(--green-d); font-weight: 600; font-size: 11px; }
[data-theme="dark"] .blink-ok { color: var(--green); }
.stable-bad { color: var(--red); font-weight: 600; font-size: 11px; }
.bsm { font-family: var(--ff-mono); font-size: 9px; font-weight: 700; padding: 3px 9px; border-radius: 100px; letter-spacing: 0.4px; white-space: nowrap; }
.bsm-ok { background: var(--green-bg); color: var(--green-d); border: 1px solid rgba(14,143,79,0.25); }
[data-theme="dark"] .bsm-ok { color: var(--green); }
.bsm-warn { background: var(--amber-bg); color: var(--amber); border: 1px solid rgba(179,118,10,0.25); }
.bsm-key { background: var(--blue-bg); color: var(--blue); border: 1px solid rgba(29,95,180,0.22); }

/* Debug / fault table */
.debug-wrap { display: flex; flex-direction: column; gap: 10px; margin: 16px 0; }
.dbrow { display: flex; gap: 0; border: 1px solid var(--border); border-radius: var(--r); overflow: hidden; background: var(--surface); }
.db-bar { width: 4px; flex-shrink: 0; }
.db-bar.red { background: var(--red); }
.db-bar.amber { background: var(--amber); }
.db-cols { flex: 1; display: grid; grid-template-columns: 1fr 1fr; gap: 0; }
.db-sym, .db-fix { padding: 14px 18px; }
.db-sym { border-right: 1px solid var(--border); }
.db-lbl { font-family: var(--ff-mono); font-size: 8px; color: var(--text3); letter-spacing: 1.5px; margin-bottom: 6px; }
.db-val { font-size: 12px; color: var(--text2); line-height: 1.6; }
.db-val strong { color: var(--text); }

/* Topic hero (legacy class kept for compatibility, mapped to page-hero look) */
.topic-hero { padding: 124px 0 36px; background: var(--bg2); border-bottom: 1px solid var(--border); }
.th-inner { display: flex; justify-content: space-between; align-items: flex-start; gap: 24px; flex-wrap: wrap; }
.th-day { font-family: var(--ff-mono); font-size: 10.5px; color: var(--green-d); letter-spacing: 1.5px; text-transform: uppercase; margin-bottom: 10px; }
[data-theme="dark"] .th-day { color: var(--green); }
.th-title { font-size: clamp(24px, 3.8vw, 36px); font-weight: 700; letter-spacing: -0.8px; color: var(--text); line-height: 1.18; margin-bottom: 12px; }
.th-sub { font-size: 14px; color: var(--text2); line-height: 1.7; max-width: 600px; margin-bottom: 16px; }
.th-meta { display: flex; gap: 8px; flex-wrap: wrap; }
.th-btns { display: flex; gap: 10px; flex-wrap: wrap; flex-shrink: 0; }
.th-btn { font-size: 12.5px; font-weight: 600; padding: 10px 18px; border-radius: 9px; border: 1px solid var(--border2); color: var(--text2); transition: all var(--tr); white-space: nowrap; }
.th-btn:hover { color: var(--text); border-color: var(--text3); background: var(--surface2); }
.th-btn.home { color: var(--green-d); border-color: rgba(14,143,79,0.25); background: var(--green-bg); }
[data-theme="dark"] .th-btn.home { color: var(--green); }

/* ══════════════════════════════════════════
   RESPONSIVE — TABLET
══════════════════════════════════════════ */
@media (max-width: 980px) {
  .nav-center { display: none; }
  .nav-clock-block { display: none; }
  .nav-mobile-clock-inline { display: flex; }
  .nav-cta-btn { display: none; }
  .nav-mobile-right { display: flex; }

  .summary-grid { grid-template-columns: repeat(2, 1fr); }
  .explore-grid { grid-template-columns: repeat(2, 1fr); }
  .live-strip { grid-template-columns: 1fr; }
  .about-grid { grid-template-columns: 1fr; gap: 36px; }
  .phase-meta { display: none; }
  .topic-layout { grid-template-columns: 1fr; }
  .toc { position: static; margin-bottom: 28px; }
  .db-cols { grid-template-columns: 1fr; }
  .db-sym { border-right: none; border-bottom: 1px solid var(--border); }
}

/* ══════════════════════════════════════════
   RESPONSIVE — MOBILE
══════════════════════════════════════════ */
@media (max-width: 620px) {
  .nav-inner { padding: 0 14px; }
  .nav-logo-sub { display: none; }
  .nav-mobile-clock-inline { display: none; }

  .home-hero-inner { padding: 76px 16px 40px; }
  .hh-title { letter-spacing: -0.8px; }
  .hh-desc { font-size: 13px; }
  .hh-stats { flex-direction: column; }
  .hhs-div { display: none; }
  .hhs-item { flex-direction: row; justify-content: space-between; width: 100%; padding: 10px 14px; }

  .summary-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
  .summary-card { padding: 16px; }
  .explore-grid { grid-template-columns: 1fr; }
  .live-strip { padding: 4px; }

  .stats-bar-inner { flex-wrap: nowrap; overflow-x: auto; padding: 0 8px; }
  .sbar-item { min-width: 150px; padding: 10px 12px; }
  .sbar-div { display: none; }

  .page-hero, .topic-hero { padding: 100px 0 28px; }
  .syllabus-section { padding: 36px 0 56px; }
  .cards-grid { grid-template-columns: 1fr; }
  .phase-label-row { gap: 10px; }
  .phase-name { font-size: 15px; }

  .about-section { padding: 40px 0; }
  .section-title, .page-title { font-size: clamp(20px, 6vw, 28px); }

  .duty-grid, .two-col, .mnemonic-grid, .flow-row4, .flow-row3, .hc-row2, .hc-row3 { grid-template-columns: 1fr; }
  .rb-grid { grid-template-columns: 1fr; }
  .rb-item:nth-child(even) { border-right: 1px solid var(--border); }
  .rb-item:nth-last-child(-n+2) { border-bottom: 1px solid var(--border); }
  .rb-item:last-child { border-bottom: none; }
  .promo-chain { flex-direction: column; align-items: flex-start; }
  .pc-arrow { transform: rotate(90deg); }
  .fb-cat { min-width: 80px; font-size: 9px; }

  .led-head, .led-row { grid-template-columns: 1fr; gap: 4px; }
  .led-head { display: none; }
  .l-state { display: flex; align-items: center; gap: 8px; }

  .device-diag { gap: 8px; }
  .dd-side { min-width: 70px; padding: 10px; }

  .footer-top, .footer-inner { flex-direction: column; align-items: flex-start; }
  .footer-bottom { flex-direction: column; gap: 4px; }

  .next-strip, .ns-pair, .phase-nav-strip { padding: 20px; }
}