/* =========================================
   style.css — Meshtastic 斷網演練指引
   ========================================= */

/* ---- Design Tokens ---- */
:root {
  --bg-base: #f0f4f8;
  --bg-surface: #e8edf3;
  --bg-card: #ffffff;
  --bg-card-hover: #f8fafc;

  --accent: #0284c7;
  --accent-dim: #0369a1;
  --accent-glow: rgba(2, 132, 199, 0.12);

  --warn: #b45309;
  --warn-glow: rgba(180, 83, 9, 0.12);
  --warn-dim: #92400e;

  --danger: #dc2626;
  --danger-glow: rgba(220, 38, 38, 0.1);

  --success: #059669;
  --success-dim: #047857;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-code: #0369a1;

  --border: rgba(0, 0, 0, 0.1);
  --border-accent: rgba(2, 132, 199, 0.3);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;

  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.08);
  --shadow-glow: 0 0 40px var(--accent-glow);

  --nav-height: 64px;
  --font-sans: 'Noto Sans TC', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;
}

/* ---- Reset & Base ---- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s, opacity 0.2s;
}
a:hover { opacity: 0.8; }

strong { font-weight: 700; }

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: rgba(125, 211, 252, 0.1);
  color: var(--text-code);
  border: 1px solid rgba(125, 211, 252, 0.2);
  border-radius: 4px;
  padding: 0.1em 0.4em;
}

ul { list-style: none; }

img, svg { display: block; }

/* ---- Layout ---- */
.container {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---- Scroll Reveal ---- */
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---- Navigation ---- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(240, 244, 248, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  transition: background 0.3s, box-shadow 0.3s;
}
.nav.scrolled {
  background: rgba(240, 244, 248, 0.98);
  box-shadow: 0 2px 32px rgba(0, 0, 0, 0.1);
}
.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: -0.01em;
  text-decoration: none;
  flex-shrink: 0;
}
.nav-logo-icon { font-size: 1.3rem; }
.nav-logo .accent { color: var(--accent); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  flex-wrap: wrap;
}
.nav-link {
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: color 0.2s, background 0.2s;
  text-decoration: none;
  white-space: nowrap;
}
.nav-link:hover,
.nav-link.active {
  color: var(--accent);
  background: var(--accent-glow);
  opacity: 1;
}

.nav-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  border-radius: var(--radius-sm);
}
.nav-menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-secondary);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}
.nav-menu-btn.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-menu-btn.open span:nth-child(2) { opacity: 0; }
.nav-menu-btn.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---- Hero ---- */
.hero {
  position: relative;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-height) + 48px) 24px 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(2, 132, 199, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(2, 132, 199, 0.07) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 50%, black 40%, transparent 100%);
}

.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
}
.glow-1 {
  width: 600px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(2, 132, 199, 0.12) 0%, transparent 70%);
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
}
.glow-2 {
  width: 400px;
  height: 300px;
  background: radial-gradient(ellipse, rgba(14, 165, 233, 0.08) 0%, transparent 70%);
  bottom: 100px;
  right: 5%;
}

/* Radar animation */
.hero-radar {
  position: absolute;
  right: 8%;
  top: 50%;
  transform: translateY(-50%);
  width: 280px;
  height: 280px;
  opacity: 0.18;
}
.radar-ring {
  position: absolute;
  inset: 0;
  border: 1px solid var(--accent);
  border-radius: 50%;
  transform: scale(0);
  animation: radar-pulse 3s ease-out infinite;
}
.ring-2 { animation-delay: 1s; }
.ring-3 { animation-delay: 2s; }
.radar-dot {
  position: absolute;
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  box-shadow: 0 0 16px var(--accent);
}

@keyframes radar-pulse {
  0% { transform: scale(0.1); opacity: 1; }
  100% { transform: scale(1); opacity: 0; }
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 760px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(34, 211, 238, 0.1);
  border: 1px solid var(--border-accent);
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  padding: 6px 14px;
  border-radius: 100px;
}
.badge-dot {
  width: 7px;
  height: 7px;
  background: var(--accent);
  border-radius: 50%;
  animation: blink 1.5s ease-in-out infinite;
}
@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

.hero-title {
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: clamp(2.4rem, 7vw, 4.5rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.1;
}
.title-line {
  background: linear-gradient(135deg in oklch, var(--accent) 0%, #0ea5e9 50%, #7c3aed 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.title-sub {
  font-size: clamp(1.1rem, 3vw, 1.6rem);
  font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: -0.01em;
  -webkit-text-fill-color: var(--text-secondary);
}

.hero-desc {
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--text-secondary);
  max-width: 520px;
  line-height: 1.8;
}

.hero-cta {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  justify-content: center;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 0.95rem;
  padding: 13px 28px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
  text-decoration: none;
  border: none;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); opacity: 1; }
.btn:active { transform: translateY(0); }

.btn-primary {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dim) 100%);
  color: #ffffff;
  box-shadow: 0 4px 24px rgba(2, 132, 199, 0.3);
}
.btn-primary:hover {
  box-shadow: 0 8px 32px rgba(2, 132, 199, 0.45);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}
.btn-ghost:hover {
  color: var(--text-primary);
  border-color: rgba(0, 0, 0, 0.2);
  background: rgba(0, 0, 0, 0.04);
}

/* Scroll hint */
.scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}
.scroll-arrow {
  width: 20px;
  height: 20px;
  border-right: 2px solid var(--text-muted);
  border-bottom: 2px solid var(--text-muted);
  transform: rotate(45deg);
  animation: bounce 1.5s ease-in-out infinite;
  margin-top: -8px;
}
@keyframes bounce {
  0%, 100% { transform: rotate(45deg) translateY(0); opacity: 0.5; }
  50% { transform: rotate(45deg) translateY(6px); opacity: 1; }
}

/* ---- Sections ---- */
.section {
  padding: 96px 0;
  position: relative;
}
.section:nth-child(even) {
  background: rgba(226, 232, 240, 0.5);
}

.section-header {
  margin-bottom: 48px;
}
.section-number {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.1em;
  margin-bottom: 4px;
}
.section-label {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 10px;
}
.section-title {
  font-size: clamp(1.7rem, 4vw, 2.5rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  line-height: 1.2;
}
.section-desc {
  margin-top: 12px;
  color: var(--text-secondary);
  font-size: 1rem;
}

/* ---- Alert ---- */
.alert {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 18px 20px;
  border-radius: var(--radius-md);
  margin-bottom: 36px;
  font-size: 0.95rem;
  line-height: 1.6;
}
.alert-urgent {
  background: rgba(251, 191, 36, 0.1);
  border: 1px solid rgba(251, 191, 36, 0.3);
  color: var(--text-primary);
}
.alert-icon { font-size: 1.2rem; flex-shrink: 0; margin-top: 1px; }

/* ---- Checklist ---- */
.checklist {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.checklist-item {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition: border-color 0.2s, background 0.2s, transform 0.2s;
}
.checklist-item:first-child { border-radius: var(--radius-md) var(--radius-md) var(--radius-sm) var(--radius-sm); }
.checklist-item:last-child  { border-radius: var(--radius-sm) var(--radius-sm) var(--radius-md) var(--radius-md); }
.checklist-item:only-child  { border-radius: var(--radius-md); }

.checklist-item:hover {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
  transform: translateX(4px);
}

.check-icon {
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: var(--accent-glow);
  color: var(--accent);
  padding: 10px;
}
.check-icon--map    { background: rgba(167, 139, 250, 0.12); color: #a78bfa; }
.check-icon--signal { background: rgba(52, 211, 153, 0.12); color: var(--success); }
.check-icon--mode   { background: rgba(251, 191, 36, 0.12); color: var(--warn); }
.check-icon--battery { background: rgba(248, 113, 113, 0.12); color: var(--danger); }

.check-body { flex: 1; min-width: 0; }
.check-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}
.check-desc {
  color: var(--text-secondary);
  font-size: 0.93rem;
  line-height: 1.65;
}

.check-links {
  display: flex;
  gap: 10px;
  margin-top: 14px;
  flex-wrap: wrap;
}
.app-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s;
}
.app-badge:hover { transform: translateY(-2px); opacity: 1; }
.android {
  background: rgba(52, 211, 153, 0.12);
  color: var(--success);
  border: 1px solid rgba(52, 211, 153, 0.25);
}
.ios {
  background: rgba(125, 211, 252, 0.12);
  color: var(--text-code);
  border: 1px solid rgba(125, 211, 252, 0.25);
}

.info-box {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 12px;
  padding: 10px 16px;
  background: rgba(34, 211, 238, 0.06);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  flex-wrap: wrap;
}
.info-label {
  color: var(--text-muted);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.channel-code {
  font-size: 0.88rem;
}

.tip-box {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin-top: 12px;
  padding: 12px 16px;
  background: rgba(251, 191, 36, 0.08);
  border: 1px solid rgba(251, 191, 36, 0.2);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
}
.tip-icon { flex-shrink: 0; font-size: 1rem; margin-top: 1px; }

/* ---- Scenario Section ---- */
.scenario-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  margin-bottom: 40px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  position: relative;
  overflow: hidden;
}
.scenario-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--warn), var(--danger));
}

.scenario-tag {
  display: inline-flex;
  align-items: center;
  background: rgba(251, 191, 36, 0.15);
  color: var(--warn);
  border: 1px solid rgba(251, 191, 36, 0.3);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  padding: 4px 12px;
  border-radius: 100px;
  width: fit-content;
}

.scenario-desc p {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.75;
}
.scenario-desc p + p { margin-top: 8px; }
.scenario-desc strong { color: var(--text-primary); }

.scenario-icons {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 8px;
  font-size: 2rem;
}
.scenario-divider {
  color: var(--text-muted);
  font-size: 1.2rem;
  font-family: var(--font-mono);
}

/* Steps */
.steps {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
}
.steps-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 28px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
}

.step {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}
.step + .step {
  margin-top: 28px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}
.step-num {
  width: 36px;
  height: 36px;
  min-width: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--accent), var(--accent-dim));
  color: #ffffff;
  font-weight: 900;
  font-size: 0.9rem;
  border-radius: 50%;
  box-shadow: 0 0 16px rgba(2, 132, 199, 0.25);
}
.step-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}
.step-desc {
  color: var(--text-secondary);
  font-size: 0.93rem;
  line-height: 1.7;
}
.step-note {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 12px;
  padding: 8px 12px;
  background: rgba(0, 0, 0, 0.04);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  color: var(--text-muted);
}

.message-example {
  margin-top: 16px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
}
.message-bubble {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: rgba(2, 132, 199, 0.08);
  border: 1px solid var(--border-accent);
  border-radius: 16px 16px 16px 4px;
  padding: 12px 18px;
  font-size: 0.95rem;
  color: var(--text-primary);
  font-style: italic;
}
.message-icon { font-size: 1rem; }
.message-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  padding-left: 4px;
}

/* ---- Principles ---- */
.principles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.principle-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: border-color 0.2s, background 0.2s, transform 0.25s;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.principle-card:hover {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
  transform: translateY(-4px);
}

.principle-icon {
  font-size: 2rem;
  line-height: 1;
}
.principle-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.35;
}
.principle-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ---- Troubleshoot ---- */
.trouble-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.trouble-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  border: 1px solid transparent;
}
.trouble-card--yellow {
  border-color: rgba(251, 191, 36, 0.25);
  background: linear-gradient(180deg, rgba(251,191,36,0.06) 0%, var(--bg-card) 30%);
}
.trouble-card--red {
  border-color: rgba(248, 113, 113, 0.25);
  background: linear-gradient(180deg, rgba(248,113,113,0.06) 0%, var(--bg-card) 30%);
}

.trouble-header {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.trouble-tag {
  display: inline-flex;
  width: fit-content;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 100px;
}
.trouble-card--yellow .trouble-tag {
  background: rgba(251, 191, 36, 0.15);
  color: var(--warn);
  border: 1px solid rgba(251, 191, 36, 0.3);
}
.trouble-card--red .trouble-tag {
  background: rgba(248, 113, 113, 0.15);
  color: var(--danger);
  border: 1px solid rgba(248, 113, 113, 0.3);
}
.trouble-card--green {
  border-color: rgba(52, 211, 153, 0.25);
  background: linear-gradient(180deg, rgba(52,211,153,0.06) 0%, var(--bg-card) 30%);
}
.trouble-card--green .trouble-tag {
  background: rgba(52, 211, 153, 0.15);
  color: var(--success);
  border: 1px solid rgba(52, 211, 153, 0.3);
}
.trouble-card--green .cause-num {
  background: rgba(52, 211, 153, 0.15);
  color: var(--success);
  border: 1px solid rgba(52, 211, 153, 0.25);
}

.trouble-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.35;
}

.status-display {
  background: rgba(0, 0, 0, 0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.status-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.os-label {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  background: rgba(0,0,0,0.07);
  padding: 2px 8px;
  border-radius: 4px;
  min-width: 56px;
  text-align: center;
}
.status-icon-wrapper {
  display: flex;
  align-items: center;
  gap: 8px;
}
.status-screenshot {
  height: 40px;
  width: auto;
  border-radius: 6px;
  object-fit: contain;
  border: 1px solid var(--border);
  background: transparent;
  flex-shrink: 0;
}
.status-screenshot--full {
  height: auto;
  width: 100%;
  max-height: 180px;
  object-fit: contain;
  object-position: left center;
  margin-top: 10px;
  border-radius: var(--radius-sm);
}
.status-text {
  font-size: 0.8rem;
}

.trouble-meaning, .trouble-cause {
  font-size: 0.9rem;
}
.meaning-title, .cause-title {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 8px;
}
.trouble-meaning p, .trouble-cause p {
  color: var(--text-secondary);
  line-height: 1.65;
}
.trouble-cause ul {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.trouble-cause li {
  color: var(--text-secondary);
  padding-left: 16px;
  position: relative;
  line-height: 1.6;
}
.trouble-cause li::before {
  content: '›';
  position: absolute;
  left: 0;
  color: var(--text-muted);
  font-weight: 700;
}

.trouble-action {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 16px;
  background: rgba(251, 191, 36, 0.08);
  border: 1px solid rgba(251, 191, 36, 0.2);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}
.action-icon { font-size: 1.1rem; flex-shrink: 0; }

.trouble-causes-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.cause-item {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
}
.cause-num {
  width: 24px;
  height: 24px;
  min-width: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(248, 113, 113, 0.15);
  color: var(--danger);
  border: 1px solid rgba(248, 113, 113, 0.25);
  border-radius: 50%;
  font-size: 0.75rem;
  font-weight: 700;
  margin-top: 2px;
}

/* ---- Crisis ---- */
.section-crisis {
  background: radial-gradient(ellipse 80% 60% at 50% 50%, rgba(220, 38, 38, 0.05) 0%, transparent 70%);
}

.crisis-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.crisis-card {
  position: relative;
  border-radius: var(--radius-xl);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  overflow: hidden;
  border: 1px solid transparent;
}
.crisis-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(135deg, rgba(0,0,0,0.06), rgba(0,0,0,0.02));
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask-composite: exclude;
  -webkit-mask-composite: xor;
  pointer-events: none;
}
.crisis-card--bandwidth {
  background: linear-gradient(135deg, rgba(2, 132, 199, 0.08), rgba(240, 244, 248, 0.9));
  border-color: rgba(2, 132, 199, 0.2);
}
.crisis-card--warning {
  background: linear-gradient(135deg, rgba(220, 38, 38, 0.08), rgba(240, 244, 248, 0.9));
  border-color: rgba(220, 38, 38, 0.2);
}

.crisis-num {
  position: absolute;
  top: 20px;
  right: 24px;
  font-family: var(--font-mono);
  font-size: 4rem;
  font-weight: 900;
  color: rgba(0,0,0,0.05);
  line-height: 1;
  pointer-events: none;
}
.crisis-icon { font-size: 2.2rem; }
.crisis-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}
.crisis-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.7;
}
.crisis-desc + .crisis-desc { margin-top: 8px; }

/* ---- Review ---- */
.review-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.review-item {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 24px 28px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition: border-color 0.2s, background 0.2s, transform 0.2s;
}
.review-item:hover {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
  transform: translateX(6px);
}

.review-icon {
  font-size: 1.8rem;
  flex-shrink: 0;
  line-height: 1;
  margin-top: 2px;
}
.review-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}
.review-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.7;
}


/* ---- FAQ ---- */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.2s;
}
.faq-item:first-child { border-radius: var(--radius-md) var(--radius-md) var(--radius-sm) var(--radius-sm); }
.faq-item:last-child  { border-radius: var(--radius-sm) var(--radius-sm) var(--radius-md) var(--radius-md); }

.faq-item[open],
.faq-item:hover {
  border-color: var(--border-accent);
}

.faq-q {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 24px;
  cursor: pointer;
  list-style: none;
  user-select: none;
  -webkit-user-select: none;
}
.faq-q::-webkit-details-marker { display: none; }

.faq-q-text {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.45;
}

.faq-chevron {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  border-right: 2px solid var(--accent);
  border-bottom: 2px solid var(--accent);
  transform: rotate(45deg);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  margin-top: -4px;
}
.faq-item[open] .faq-chevron {
  transform: rotate(-135deg);
  margin-top: 4px;
}

.faq-a {
  padding: 0 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  border-top: 1px solid var(--border);
  padding-top: 16px;
}
.faq-a p {
  font-size: 0.93rem;
  color: var(--text-secondary);
  line-height: 1.75;
}
.faq-a ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-left: 4px;
}
.faq-a li {
  font-size: 0.93rem;
  color: var(--text-secondary);
  padding-left: 16px;
  position: relative;
  line-height: 1.65;
}
.faq-a li::before {
  content: '›';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}
.faq-a strong {
  color: var(--text-primary);
}

/* ---- Footer ---- */

.footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  padding: 40px 0 32px;
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 14px;
}
.footer-logo { font-size: 1.8rem; }
.footer-title {
  font-weight: 700;
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: var(--font-mono);
}
.footer-sub {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-top: 2px;
}
.footer-links {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}
.footer-link {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
}
.footer-link:hover { color: var(--accent); opacity: 1; }
.footer-copy {
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  padding-top: 20px;
}

/* ---- Scroll-driven progress bar ---- */
@supports (animation-timeline: scroll()) {
  body::after {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent), #a78bfa);
    z-index: 200;
    width: 100%;
    transform-origin: left;
    transform: scaleX(0);
    animation: progress linear both;
    animation-timeline: scroll(root);
  }
  @keyframes progress {
    to { transform: scaleX(1); }
  }
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    padding: 16px;
    background: rgba(240, 244, 248, 0.98);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    gap: 4px;
  }
  .nav-links.open { display: flex; }
  .nav-menu-btn { display: flex; }
  .nav-link { padding: 12px 16px; font-size: 1rem; }

  .hero-radar { display: none; }

  .trouble-cards { grid-template-columns: 1fr; }
  .crisis-grid { grid-template-columns: 1fr; }
  .principles-grid { grid-template-columns: 1fr; }

  .checklist-item { flex-direction: column; }

  .section { padding: 64px 0; }
  .section-header { margin-bottom: 32px; }
}

@media (max-width: 480px) {
  .hero-cta { flex-direction: column; width: 100%; }
  .btn { width: 100%; }

  .scenario-card, .steps { padding: 20px; }
  .checklist-item { padding: 18px; }
  .review-item { padding: 18px; }
  .crisis-card { padding: 24px 20px; }
}

/* ---- Reduced Motion ---- */
@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .badge-dot { animation: none; }
  .radar-ring { animation: none; }
  .scroll-arrow { animation: none; }
  html { scroll-behavior: auto; }
}