/* ===== BTC MINE CLOUD — World-Class Design System ===== */
/* Black / White / Dark Gray — Precision Minimal */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

/* === Dark Theme (default) === */
:root, [data-theme="dark"] {
  --black: #000000;
  --bg-0: #0b0b0b;
  --bg-1: #121212;
  --bg-2: #1a1a1a;
  --bg-3: #222222;
  --bg-4: #2a2a2a;
  --bg-5: #333333;

  --border-1: #262626;
  --border-2: #333333;
  --border-3: #444444;

  --text-primary: #f0f0f0;
  --text-secondary: #a0a0a0;
  --text-muted: #777777;
  --text-dim: #555555;

  --white: #ffffff;
  --accent: #ffffff;
  --accent-dim: rgba(255,255,255,0.07);
  --accent-hover: rgba(255,255,255,0.14);

  --green: #00d672;
  --green-dim: rgba(0,214,114,0.10);
  --green-glow: rgba(0,214,114,0.15);
  --red: #ff4d4d;
  --red-dim: rgba(255,77,77,0.10);
  --blue: #4da6ff;
  --blue-dim: rgba(77,166,255,0.10);
  --purple: #a78bfa;
  --purple-dim: rgba(167,139,250,0.10);
  --cyan: #22d3ee;
  --cyan-dim: rgba(34,211,238,0.08);

  --nav-bg: rgba(0,0,0,0.85);
  --nav-mobile-bg: rgba(0,0,0,0.95);
  --modal-overlay: rgba(0,0,0,0.8);
  --selection-bg: rgba(255,255,255,0.15);
  --selection-color: #ffffff;
  --scrollbar-thumb: #444444;
  --scrollbar-hover: #666666;
  --input-focus-ring: rgba(255,255,255,0.05);
  --btn-primary-bg: #ffffff;
  --btn-primary-color: #000000;
  --btn-primary-hover: #e0e0e0;
  --period-active-bg: #ffffff;
  --period-active-color: #000000;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;

  --radius-s: 6px;
  --radius: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 20px;

  --shadow-subtle: 0 1px 2px rgba(0,0,0,0.5);
  --shadow-card: 0 2px 8px rgba(0,0,0,0.4);
  --shadow-elevated: 0 8px 32px rgba(0,0,0,0.6);
  --glow-white: 0 0 20px rgba(255,255,255,0.03);
  --glow-green: 0 0 20px rgba(0,214,114,0.1);
}

/* === Light Theme === */
[data-theme="light"] {
  --black: #ffffff;
  --bg-0: #f7f7f8;
  --bg-1: #ffffff;
  --bg-2: #f0f0f2;
  --bg-3: #e8e8ec;
  --bg-4: #dddde2;
  --bg-5: #d0d0d6;

  --border-1: #e0e0e4;
  --border-2: #d0d0d6;
  --border-3: #b8b8c0;

  --text-primary: #1a1a1a;
  --text-secondary: #555555;
  --text-muted: #777777;
  --text-dim: #999999;

  --white: #1a1a1a;
  --accent: #1a1a1a;
  --accent-dim: rgba(0,0,0,0.04);
  --accent-hover: rgba(0,0,0,0.08);

  --green: #00a85a;
  --green-dim: rgba(0,168,90,0.08);
  --green-glow: rgba(0,168,90,0.12);
  --red: #e53535;
  --red-dim: rgba(229,53,53,0.08);
  --blue: #2b7dd9;
  --blue-dim: rgba(43,125,217,0.08);
  --purple: #7c5cbf;
  --purple-dim: rgba(124,92,191,0.08);
  --cyan: #0ea5c4;
  --cyan-dim: rgba(14,165,196,0.06);

  --nav-bg: rgba(255,255,255,0.88);
  --nav-mobile-bg: rgba(255,255,255,0.97);
  --modal-overlay: rgba(0,0,0,0.4);
  --selection-bg: rgba(0,0,0,0.12);
  --selection-color: #000000;
  --scrollbar-thumb: #c0c0c0;
  --scrollbar-hover: #999999;
  --input-focus-ring: rgba(0,0,0,0.06);
  --btn-primary-bg: #1a1a1a;
  --btn-primary-color: #ffffff;
  --btn-primary-hover: #333333;
  --period-active-bg: #1a1a1a;
  --period-active-color: #ffffff;

  --shadow-subtle: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-card: 0 2px 8px rgba(0,0,0,0.06);
  --shadow-elevated: 0 8px 32px rgba(0,0,0,0.12);
  --glow-white: none;
  --glow-green: 0 0 20px rgba(0,168,90,0.08);
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--black);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--selection-bg); color: var(--selection-color); }
a { color: var(--text-primary); text-decoration: none; transition: opacity 0.2s; }
a:hover { opacity: 0.7; }

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--scrollbar-hover); }

/* ===== Layout ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.container-wide { max-width: 1400px; margin: 0 auto; padding: 0 24px; }

/* ===== Navigation Bar ===== */
.nav-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: 56px;
  background: var(--nav-bg);
  backdrop-filter: blur(24px) saturate(1.2);
  -webkit-backdrop-filter: blur(24px) saturate(1.2);
  border-bottom: 1px solid var(--border-1);
}

.nav-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  text-decoration: none;
}

.nav-logo:hover { opacity: 1; }

.nav-logo-icon {
  width: 28px;
  height: 28px;
  border: 1.5px solid var(--white);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 13px;
  color: var(--white);
  letter-spacing: -0.5px;
}

.nav-logo-text {
  font-weight: 700;
  font-size: 15px;
  letter-spacing: -0.3px;
  color: var(--white);
}

.nav-logo-text span {
  font-weight: 400;
  color: var(--text-muted);
  margin-left: 2px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-link {
  padding: 6px 14px;
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  transition: all 0.15s ease;
  white-space: nowrap;
  text-decoration: none;
  letter-spacing: -0.1px;
}

.nav-link:hover {
  color: var(--text-secondary);
  background: var(--accent-dim);
  opacity: 1;
}

.nav-link.active {
  color: var(--white);
  background: var(--accent-dim);
}

.nav-link.active::after {
  content: '';
  display: block;
  width: 100%;
  height: 0;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-shrink: 0;
}

.nav-ticker {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 5px 12px;
  border-radius: var(--radius);
  border: 1px solid var(--border-1);
  background: var(--bg-2);
}

.nav-ticker-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.nav-ticker-price {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--white);
}

.nav-ticker-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--green);
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; box-shadow: 0 0 4px var(--green); }
  50% { opacity: 0.4; box-shadow: none; }
}

/* Mobile nav */
.nav-mobile-toggle {
  display: none;
  width: 36px; height: 36px;
  align-items: center; justify-content: center;
  background: none; border: 1px solid var(--border-2);
  border-radius: var(--radius); cursor: pointer; color: var(--text-primary);
  font-size: 18px;
}

@media (max-width: 900px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 56px; left: 0; right: 0;
    background: var(--nav-mobile-bg);
    backdrop-filter: blur(24px);
    border-bottom: 1px solid var(--border-1);
    padding: 8px;
    gap: 2px;
  }
  .nav-links.open .nav-link {
    padding: 12px 16px;
    font-size: 14px;
    border-radius: var(--radius);
  }
  .nav-mobile-toggle { display: flex; }
}

/* Body offset for fixed nav */
body { padding-top: 56px; }

/* ===== Hero ===== */
.hero {
  padding: 72px 0 48px;
  text-align: center;
}

.hero h1 {
  font-size: 3.25rem;
  font-weight: 800;
  letter-spacing: -1.5px;
  line-height: 1.1;
  color: var(--white);
  margin-bottom: 16px;
}

.hero .subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.7;
  font-weight: 400;
}

.hero-badges {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 28px;
  flex-wrap: wrap;
}

.hero-badge {
  padding: 6px 16px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 500;
  background: transparent;
  border: 1px solid var(--border-2);
  color: var(--text-muted);
  letter-spacing: 0.2px;
}

/* ===== Stats Grid ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1px;
  background: var(--border-1);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 32px;
}

.stat-card {
  background: var(--bg-1);
  padding: 20px 24px;
  text-align: left;
}

.stat-card .label {
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.8px;
  font-weight: 600;
  margin-bottom: 8px;
}

.stat-card .value {
  font-size: 1.5rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--white);
  letter-spacing: -0.5px;
}

.stat-card .value.green { color: var(--green); }
.stat-card .value.red { color: var(--red); }
.stat-card .value.accent { color: var(--white); }

.stat-card .sub {
  font-size: 11px;
  color: var(--text-dim);
  margin-top: 4px;
  font-weight: 500;
}

/* ===== Cards ===== */
.card {
  background: var(--bg-1);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: border-color 0.2s;
}

.card:hover { border-color: var(--border-2); }

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-1);
}

.card-header h2 {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.2px;
  color: var(--text-primary);
}

.badge {
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 999px;
  font-weight: 600;
  letter-spacing: 0.3px;
  text-transform: uppercase;
}

.badge-green { background: var(--green-dim); color: var(--green); border: 1px solid rgba(0,214,114,0.15); }
.badge-red { background: var(--red-dim); color: var(--red); border: 1px solid rgba(255,77,77,0.15); }
.badge-blue { background: var(--blue-dim); color: var(--blue); border: 1px solid rgba(77,166,255,0.15); }
.badge-amber { background: var(--accent-dim); color: var(--text-secondary); border: 1px solid var(--border-2); }
.badge-purple { background: var(--purple-dim); color: var(--purple); border: 1px solid rgba(167,139,250,0.15); }

/* ===== Tables ===== */
.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-1);
}

table { width: 100%; border-collapse: collapse; }

thead { background: var(--bg-2); }

th {
  padding: 10px 16px;
  text-align: left;
  font-weight: 600;
  color: var(--text-muted);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  white-space: nowrap;
}

td {
  padding: 12px 16px;
  border-top: 1px solid var(--border-1);
  font-size: 13px;
  white-space: nowrap;
  color: var(--text-secondary);
}

tr { transition: background 0.1s; }
tr:hover td { background: var(--accent-dim); }

td.mono { font-family: var(--font-mono); font-size: 12px; }
td.green { color: var(--green); }
td.red { color: var(--red); }
td.accent { color: var(--white); font-weight: 600; }

/* ===== Forms ===== */
.form-group { margin-bottom: 16px; }

.form-group label {
  display: block;
  font-size: 11px;
  color: var(--text-muted);
  margin-bottom: 6px;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
}

input[type="number"],
input[type="text"],
select {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-0);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 13px;
  transition: all 0.15s;
  appearance: none;
  -webkit-appearance: none;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--text-muted);
  box-shadow: 0 0 0 3px var(--input-focus-ring);
}

select {
  background-image: url("data:image/svg+xml,%3Csvg width='10' height='6' viewBox='0 0 10 6' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%23555' fill='none' stroke-width='1.5' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 32px;
}

input[type="range"] {
  width: 100%;
  height: 4px;
  -webkit-appearance: none;
  background: var(--border-2);
  border-radius: 2px;
  outline: none;
  margin: 12px 0;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  background: var(--white);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 8px rgba(255,255,255,0.2);
  transition: box-shadow 0.2s;
}

input[type="range"]::-webkit-slider-thumb:hover {
  box-shadow: 0 0 16px rgba(255,255,255,0.3);
}

.range-labels {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 24px;
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all 0.15s;
  font-family: var(--font-sans);
  letter-spacing: -0.1px;
}

.btn-primary {
  background: var(--btn-primary-bg);
  color: var(--btn-primary-color);
}

.btn-primary:hover {
  background: var(--btn-primary-hover);
  box-shadow: 0 0 24px rgba(255,255,255,0.1);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-2);
}

.btn-secondary:hover { border-color: var(--text-muted); }

.btn-large {
  padding: 14px 36px;
  font-size: 14px;
  border-radius: var(--radius-lg);
}

.btn-green {
  background: var(--green);
  color: var(--black);
}

.btn-green:hover {
  background: #00c066;
  box-shadow: var(--glow-green);
}

.btn-red { background: var(--red); color: var(--white); }
.btn-red:hover { background: #e63e3e; }

/* ===== Period Tabs ===== */
.period-tabs {
  display: flex;
  gap: 2px;
  background: var(--bg-2);
  border-radius: var(--radius-lg);
  padding: 3px;
  margin-bottom: 28px;
  overflow-x: auto;
}

.period-tab {
  flex: 1;
  padding: 9px 20px;
  border-radius: var(--radius);
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
  font-family: var(--font-sans);
  letter-spacing: -0.1px;
}

.period-tab:hover { color: var(--text-secondary); }

.period-tab.active {
  background: var(--period-active-bg);
  color: var(--period-active-color);
  box-shadow: var(--shadow-subtle);
}

/* ===== Contract Cards ===== */
.contracts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 12px;
  margin: 24px 0;
}

.contract-card {
  background: var(--bg-1);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-xl);
  padding: 28px 24px;
  text-align: center;
  transition: all 0.2s;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.contract-card:hover {
  border-color: var(--border-3);
  transform: translateY(-2px);
  box-shadow: var(--shadow-elevated);
}

.contract-card.popular { border-color: var(--white); }
.contract-card.popular::before {
  content: 'HOT';
  position: absolute;
  top: 12px;
  right: -20px;
  background: var(--white);
  color: var(--black);
  padding: 2px 28px;
  font-size: 9px;
  font-weight: 800;
  transform: rotate(45deg);
  letter-spacing: 1px;
}

.contract-card .period {
  font-size: 2rem;
  font-weight: 800;
  color: var(--white);
  letter-spacing: -1px;
}

.contract-card .period-label {
  font-size: 12px;
  color: var(--text-dim);
  margin-bottom: 16px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.contract-card .price {
  font-size: 1.4rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--white);
  margin: 12px 0 4px;
  letter-spacing: -0.5px;
}

.contract-card .price-sub {
  font-size: 11px;
  color: var(--text-dim);
  margin-bottom: 16px;
}

.contract-card .metric {
  display: flex;
  justify-content: space-between;
  padding: 7px 0;
  font-size: 12px;
  border-top: 1px solid var(--border-1);
}

.contract-card .metric .label { color: var(--text-dim); }
.contract-card .metric .val { color: var(--text-secondary); font-family: var(--font-mono); font-size: 11px; }

/* ===== Comparison ===== */
.comparison {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 24px;
  align-items: start;
  margin: 32px 0;
}

.comparison .vs {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1.5px solid var(--border-3);
  border-radius: 50%;
  font-weight: 800;
  color: var(--text-muted);
  font-size: 11px;
  letter-spacing: 0.5px;
  align-self: center;
}

/* ===== Result Box ===== */
.result-box {
  background: var(--bg-1);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-xl);
  padding: 28px;
  text-align: center;
}

.result-box .big-number {
  font-size: 2.5rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--white);
  letter-spacing: -1px;
}

.result-box .label {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 4px;
  font-weight: 500;
}

/* ===== Breakdown List ===== */
.breakdown { list-style: none; }

.breakdown li {
  display: flex;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px solid var(--border-1);
  font-size: 13px;
}

.breakdown li:last-child { border-bottom: none; font-weight: 600; }
.breakdown .label { color: var(--text-muted); font-weight: 400; }
.breakdown .val { font-family: var(--font-mono); font-size: 12px; color: var(--text-primary); }
.breakdown .val.green { color: var(--green); }
.breakdown .val.red { color: var(--red); }
.breakdown .val.accent { color: var(--white); }

/* ===== Scenarios ===== */
.scenario-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 20px 0;
}

.scenario-card {
  background: var(--bg-2);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-lg);
  padding: 24px;
  text-align: center;
}

.scenario-card.bearish { border-color: rgba(255,77,77,0.2); }
.scenario-card.neutral { border-color: var(--border-2); }
.scenario-card.bullish { border-color: rgba(0,214,114,0.2); }

.scenario-card .scenario-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 8px;
}

.scenario-card.bearish .scenario-label { color: var(--red); }
.scenario-card.neutral .scenario-label { color: var(--text-muted); }
.scenario-card.bullish .scenario-label { color: var(--green); }

/* ===== Halving Banner ===== */
.halving-banner {
  background: var(--bg-2);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-lg);
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 32px;
}

.halving-banner .text {
  font-size: 13px;
  color: var(--text-muted);
}

.halving-banner .text strong { color: var(--text-secondary); }

.halving-banner .countdown {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--white);
  letter-spacing: -0.3px;
}

/* ===== Gauge ===== */
.gauge-bar {
  height: 4px;
  background: var(--border-2);
  border-radius: 2px;
  overflow: hidden;
  margin: 8px 0;
}

.gauge-bar .fill {
  height: 100%;
  border-radius: 2px;
  transition: width 0.5s ease;
}

.gauge-bar .fill.green { background: var(--green); }
.gauge-bar .fill.amber { background: var(--text-muted); }
.gauge-bar .fill.red { background: var(--red); }

/* ===== Modal ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: var(--modal-overlay);
  z-index: 1000;
  display: none;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(8px);
}

.modal-overlay.active { display: flex; }

.modal {
  background: var(--bg-2);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-2xl);
  padding: 36px;
  max-width: 520px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
}

.modal h2 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 24px;
  letter-spacing: -0.3px;
}

/* ===== FAQ ===== */
.faq { margin: 48px 0; }

.faq-item {
  border-bottom: 1px solid var(--border-1);
}

.faq-item:first-child { border-top: 1px solid var(--border-1); }

.faq-q {
  padding: 18px 0;
  cursor: pointer;
  font-weight: 500;
  font-size: 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-secondary);
  transition: color 0.15s;
}

.faq-q:hover { color: var(--text-primary); }
.faq-q::after { content: '+'; font-size: 18px; color: var(--text-dim); font-weight: 300; }
.faq-item.open .faq-q { color: var(--white); }
.faq-item.open .faq-q::after { content: '\2212'; }

.faq-a {
  padding: 0 0 18px;
  color: var(--text-muted);
  font-size: 13px;
  display: none;
  line-height: 1.8;
}

.faq-item.open .faq-a { display: block; }

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border-1);
  padding: 36px 0;
  margin-top: 80px;
  text-align: center;
  color: var(--text-dim);
  font-size: 12px;
}

.footer a { color: var(--text-muted); font-size: 12px; }
.footer a:hover { color: var(--text-secondary); opacity: 1; }

.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 16px;
}

/* ===== Animations ===== */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in { animation: fadeIn 0.5s ease-out; }

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.loading { animation: pulse 1.5s ease-in-out infinite; }

/* ===== Tooltip ===== */
.tooltip { position: relative; cursor: help; }

.tooltip::after {
  content: attr(data-tip);
  position: absolute;
  bottom: calc(100% + 6px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-3);
  color: var(--text-primary);
  padding: 6px 12px;
  border-radius: var(--radius);
  font-size: 11px;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s;
  border: 1px solid var(--border-2);
}

.tooltip:hover::after { opacity: 1; }

/* ===== Special: Hashrate Display ===== */
.hashrate-display { text-align: center; margin: 24px 0; }

.hashrate-display .big {
  font-size: 4rem;
  font-weight: 900;
  font-family: var(--font-mono);
  color: var(--white);
  letter-spacing: -3px;
  line-height: 1;
}

.hashrate-display .unit {
  font-size: 14px;
  color: var(--text-dim);
  font-weight: 500;
  margin-top: 4px;
  letter-spacing: 2px;
  text-transform: uppercase;
}

/* ===== Special: Cost Breakdown Grid ===== */
.cost-breakdown {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 28px;
}

.cost-col h3 {
  font-size: 11px;
  color: var(--text-dim);
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 600;
}

/* ===== Special: Flow Diagram ===== */
.flow-diagram {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  gap: 16px;
  align-items: center;
  margin: 40px 0;
}

.flow-box {
  background: var(--bg-1);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-xl);
  padding: 28px;
  text-align: center;
}

.flow-box h3 { margin-bottom: 12px; font-size: 13px; font-weight: 700; letter-spacing: 1px; text-transform: uppercase; }

.flow-arrow {
  text-align: center;
  color: var(--text-dim);
  font-size: 1.2rem;
}

.flow-arrow .label { font-size: 10px; color: var(--text-dim); display: block; letter-spacing: 0.5px; }

/* ===== Special: Profit Highlight ===== */
.profit-highlight {
  background: var(--bg-1);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-2xl);
  padding: 40px;
  text-align: center;
  margin: 28px 0;
}

.profit-highlight .big {
  font-size: 3.5rem;
  font-weight: 900;
  font-family: var(--font-mono);
  color: var(--white);
  letter-spacing: -2px;
}

/* ===== Special: Three Column ===== */
.three-col {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 28px 0;
}

/* ===== Special: Winner Box ===== */
.winner-box {
  padding: 24px;
  border-radius: var(--radius-xl);
  text-align: center;
  margin: 28px 0;
  font-size: 14px;
  font-weight: 500;
}

.winner-box.mining { background: var(--green-dim); border: 1px solid rgba(0,214,114,0.2); color: var(--green); }
.winner-box.spot { background: var(--blue-dim); border: 1px solid rgba(77,166,255,0.2); color: var(--blue); }
.winner-box .big { font-size: 1.5rem; font-weight: 800; font-family: var(--font-mono); letter-spacing: -0.5px; }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; letter-spacing: -0.8px; }
  .hero { padding: 48px 0 32px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .contracts-grid { grid-template-columns: 1fr; }
  .comparison { grid-template-columns: 1fr; }
  .comparison .vs { align-self: center; justify-self: center; }
  .form-row { grid-template-columns: 1fr; }
  .period-tabs { flex-wrap: wrap; }
  .cost-breakdown { grid-template-columns: 1fr; }
  .scenario-grid { grid-template-columns: 1fr; }
  .flow-diagram { grid-template-columns: 1fr; }
  .flow-arrow { transform: rotate(90deg); }
  .three-col { grid-template-columns: 1fr; }
  .hashrate-display .big { font-size: 3rem; letter-spacing: -2px; }
}

@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr; }
  .container { padding: 0 16px; }
}

/* ===== Special: Offer Grid (Miner Sell) ===== */
.offer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 12px;
  margin: 24px 0;
}

.offer-card {
  background: var(--bg-1);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-xl);
  padding: 28px;
  transition: all 0.2s;
}

.offer-card:hover { border-color: var(--border-3); }

.offer-card .period-badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 999px;
  font-size: 10px;
  font-weight: 700;
  background: var(--green-dim);
  color: var(--green);
  border: 1px solid rgba(0,214,114,0.15);
  margin-bottom: 16px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.offer-card .offer-price {
  font-size: 1.75rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--white);
  letter-spacing: -0.5px;
}

.offer-card .offer-unit {
  font-size: 11px;
  color: var(--text-dim);
  margin-bottom: 16px;
}

.offer-card .offer-detail {
  display: flex;
  justify-content: space-between;
  padding: 7px 0;
  font-size: 12px;
  border-top: 1px solid var(--border-1);
}

.offer-card .offer-detail .label { color: var(--text-dim); }
.offer-card .offer-detail .val { font-family: var(--font-mono); font-size: 11px; color: var(--text-secondary); }
.offer-card .offer-detail .val.green { color: var(--green); }

.sell-btn { width: 100%; margin-top: 16px; padding: 12px; font-size: 13px; }

/* ===== Special: Advantage Cards ===== */
.advantage-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
  margin: 24px 0;
}

.advantage-card {
  background: var(--bg-1);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.advantage-card .icon {
  font-size: 1.5rem;
  margin-bottom: 16px;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--white);
}

.advantage-card h3 {
  font-size: 14px;
  margin-bottom: 8px;
  font-weight: 600;
  letter-spacing: -0.2px;
}

.advantage-card p { font-size: 12px; color: var(--text-muted); line-height: 1.7; }

/* ===== Special: Miner Config ===== */
.miner-config {
  background: var(--bg-1);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-xl);
  padding: 28px;
  margin-bottom: 24px;
}

.miner-config h3 {
  margin-bottom: 16px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.2px;
}

/* ===== Special: Invest Input ===== */
.invest-input { text-align: center; margin: 24px 0; }

.invest-input input {
  font-size: 2rem;
  text-align: center;
  max-width: 300px;
  font-weight: 700;
  background: var(--bg-0);
  border: 1.5px solid var(--border-3);
}

.invest-input label {
  display: block;
  font-size: 11px;
  color: var(--text-dim);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 600;
}

/* ===== Special: Param Section ===== */
.param-section {
  background: var(--bg-1);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-xl);
  padding: 28px;
  margin-bottom: 24px;
}

.param-section h3 {
  margin-bottom: 16px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.2px;
}

/* ===== Theme Toggle ===== */
.theme-toggle {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 16px;
  transition: all 0.2s;
  flex-shrink: 0;
}

.theme-toggle:hover {
  border-color: var(--text-muted);
  color: var(--text-primary);
}

/* Light-mode select arrow fix */
[data-theme="light"] select {
  background-image: url("data:image/svg+xml,%3Csvg width='10' height='6' viewBox='0 0 10 6' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%23777' fill='none' stroke-width='1.5' stroke-linecap='round'/%3E%3C/svg%3E");
}

/* Light-mode contract card popular border */
[data-theme="light"] .contract-card.popular { border-color: #1a1a1a; }
[data-theme="light"] .contract-card.popular::before { background: #1a1a1a; color: #ffffff; }

/* Light-mode range thumb */
[data-theme="light"] input[type="range"]::-webkit-slider-thumb {
  background: #1a1a1a;
  box-shadow: 0 0 8px rgba(0,0,0,0.2);
}

/* Smooth transition for theme switch */
body, .nav-bar, .card, .stat-card, .modal, .offer-card, .advantage-card,
.miner-config, .param-section, .flow-box, .scenario-card, .halving-banner,
.nav-ticker, .result-box, .profit-highlight, .winner-box, .contract-card {
  transition: background-color 0.3s, border-color 0.3s, color 0.3s;
}