@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;500;700&display=swap');

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

:root {
  --black:  #0a0a0b;
  --ink:    #141417;
  --ink-2:  #1d1d22;
  --line:   #2b2b32;
  --silver: #C8C8D0;
  --white:  #FFFFFF;
  --gold:   #D4A820;

  --bg:       var(--black);
  --panel:    var(--ink);
  --surface:  var(--ink-2);
  --border:   var(--line);
  --accent:   #3FB5E8;
  --text:     var(--silver);
  --text-dim: #84848f;

  --accent-rgb: 63, 181, 232;
  --gold-rgb:   212, 168, 32;

  --radius:      12px;
  --radius-sm:   8px;
  --border-soft: rgba(255, 255, 255, 0.09);
  --shadow-panel: 0 16px 40px -12px rgba(0,0,0,0.70), 0 2px 8px rgba(0,0,0,0.50);
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Roboto', sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ── Header ─────────────────────────────────────────── */
header {
  display: flex; align-items: center;
  height: 44px; padding: 0 16px; gap: 0;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.app-name {
  font-family: 'Roboto', sans-serif; font-weight: 700; font-size: 15px;
  color: var(--white); letter-spacing: 0.5px;
  text-decoration: none;
}
.app-name::first-letter { color: var(--accent); }
.nav-sep { width: 1px; height: 18px; background: var(--border); margin: 0 14px; }
.nav-back {
  font-size: 13px; color: var(--text);
  text-decoration: none; padding: 0 14px;
  transition: color 0.15s;
}
.nav-back:hover { color: var(--white); }

/* ── Layout ──────────────────────────────────────────── */
main {
  max-width: 880px;
  margin: 0 auto;
  padding: 56px 24px 80px;
  display: flex;
  flex-direction: column;
  gap: 52px;
}

/* ── Hero ────────────────────────────────────────────── */
.hero { text-align: center; }
.hero-title {
  font-family: 'Roboto', sans-serif; font-weight: 700;
  font-size: 44px; letter-spacing: 0.5px;
  color: var(--white);
}
.hero-title::first-letter { color: var(--accent); }
.hero-sub {
  margin-top: 12px;
  font-size: 14px; letter-spacing: 0.5px;
  color: var(--accent);
}
.hero-desc {
  margin-top: 24px;
  font-size: 15px; line-height: 1.8;
  color: var(--text);
  max-width: 620px; margin-left: auto; margin-right: auto;
}

/* ── Section ─────────────────────────────────────────── */
section { display: flex; flex-direction: column; gap: 18px; }

.section-title {
  font-family: 'Roboto', sans-serif; font-weight: 700;
  font-size: 20px; letter-spacing: 0.2px;
  color: var(--white);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

p { font-size: 15px; line-height: 1.8; }

/* ── Steps ───────────────────────────────────────────── */
.steps { display: flex; flex-direction: column; gap: 12px; }
.step {
  display: flex; gap: 16px; align-items: flex-start;
  background: var(--panel);
  border: 1px solid var(--border-soft);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 16px 18px;
}
.step-num {
  font-family: 'Roboto', sans-serif; font-weight: 700;
  font-size: 18px; color: var(--accent);
  flex-shrink: 0; line-height: 1.7;
}
.step-body { font-size: 14px; line-height: 1.8; }
.step-body strong { color: var(--white); font-weight: 500; }

/* ── Cards grid ──────────────────────────────────────── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 12px;
}
.card {
  background: var(--panel);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  display: flex; flex-direction: column; gap: 5px;
  transition: border-color 0.15s, transform 0.1s;
}
.card:hover { border-color: rgba(var(--accent-rgb), 0.45); transform: translateY(-1px); }
.card-label {
  font-size: 14px; font-weight: 500; color: var(--accent); letter-spacing: 0.2px;
}
.card-desc { font-size: 13px; line-height: 1.6; color: var(--text-dim); }
.card-desc strong { color: var(--white); font-weight: 500; }

code {
  font-family: 'Share Tech Mono', monospace;
  font-size: 0.9em;
  color: var(--accent);
  background: rgba(var(--accent-rgb), 0.08);
  padding: 1px 5px;
  border-radius: 4px;
}

/* ── Shortcut table ──────────────────────────────────── */
.shortcut-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.shortcut-table th {
  text-align: left; padding: 10px 12px;
  color: var(--text-dim); font-size: 13px; font-weight: 500; letter-spacing: 0.4px;
  text-transform: uppercase;
  border-bottom: 1px solid var(--border);
}
.shortcut-table td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border-soft);
  line-height: 1.6;
}
.shortcut-table tr:last-child td { border-bottom: none; }
.shortcut-group {
  padding: 12px 12px 5px;
  font-size: 13px; font-weight: 500; letter-spacing: 0.6px; text-transform: uppercase;
  color: var(--text-dim);
  border-bottom: 1px solid var(--border-soft);
}
.key {
  display: inline-block;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 2px 9px;
  font-size: 13px; font-family: 'Roboto', sans-serif; font-weight: 500;
  color: var(--white);
  box-shadow: 0 2px 0 rgba(0,0,0,0.4);
}

/* ── Modes ───────────────────────────────────────────── */
.mode-grid { display: flex; flex-direction: column; gap: 12px; }
.mode-card {
  display: flex; gap: 16px; align-items: flex-start;
  background: var(--panel);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  padding: 18px;
}
.mode-badge {
  font-family: 'Roboto', sans-serif; font-weight: 500;
  font-size: 13px; letter-spacing: 0.3px;
  color: var(--accent);
  background: rgba(var(--accent-rgb), 0.12);
  border: 1px solid rgba(var(--accent-rgb), 0.3);
  border-radius: 999px;
  padding: 5px 12px;
  white-space: nowrap;
  flex-shrink: 0;
}
.mode-badge.gold {
  color: var(--gold);
  background: rgba(var(--gold-rgb), 0.12);
  border-color: rgba(var(--gold-rgb), 0.3);
}
.mode-badge.dim {
  color: var(--text-dim);
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--border);
}
.mode-body { font-size: 14px; line-height: 1.8; }
.mode-body strong { color: var(--white); font-weight: 500; }

/* ── Footer ──────────────────────────────────────────── */
footer {
  text-align: center; padding: 28px;
  font-size: 13px; letter-spacing: 0.3px;
  color: var(--text-dim);
  border-top: 1px solid var(--border);
  margin-top: auto;
}