:root {
  --ink: #0c1b24;
  --sea: #0a4d68;
  --sea-deep: #063445;
  --foam: #e8f4f8;
  --sand: #f2ebe0;
  --accent: #c45c26;
  --ok: #1f7a4c;
  --warn: #b8860b;
  --bad: #a11d2e;
  --line: rgba(12, 27, 36, 0.12);
  --panel: rgba(255, 255, 255, 0.86);
  --shadow: 0 18px 50px rgba(6, 52, 69, 0.18);
  --font-display: "Fraunces", "Palatino Linotype", Georgia, serif;
  --font-body: "Source Sans 3", "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", Consolas, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body {
  font-family: var(--font-body);
  color: var(--ink);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(10, 77, 104, 0.28), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, rgba(196, 92, 38, 0.18), transparent 55%),
    linear-gradient(160deg, #f7f3ec 0%, #d9e8ef 45%, #c5d9e3 100%);
}

a { color: var(--sea); }
button, input, select, textarea { font: inherit; }

.app-shell {
  display: grid;
  grid-template-columns: 280px 1fr 340px;
  grid-template-rows: auto 1fr;
  min-height: 100vh;
  gap: 0;
}

.topbar {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1.4rem;
  background: linear-gradient(90deg, var(--sea-deep), var(--sea));
  color: #f5fbff;
  box-shadow: var(--shadow);
}
.brand {
  font-family: var(--font-display);
  font-size: 1.35rem;
  letter-spacing: 0.02em;
}
.brand span { opacity: 0.75; font-size: 0.85rem; margin-left: 0.6rem; font-family: var(--font-body); }
.topbar-meta { display: flex; gap: 0.75rem; align-items: center; flex-wrap: wrap; }
.pill {
  border: 1px solid rgba(255,255,255,0.25);
  border-radius: 999px;
  padding: 0.25rem 0.7rem;
  font-size: 0.82rem;
  background: rgba(255,255,255,0.08);
}
.btn {
  border: 0;
  border-radius: 10px;
  padding: 0.55rem 0.95rem;
  cursor: pointer;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
}
.btn.secondary { background: rgba(255,255,255,0.14); color: #fff; border: 1px solid rgba(255,255,255,0.25); }
.btn.ghost { background: transparent; color: var(--sea); border: 1px solid var(--line); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.btn.ok { background: var(--ok); }
.btn.bad { background: var(--bad); }

.sidebar, .coach, .main {
  min-height: 0;
}
.sidebar, .coach {
  background: var(--panel);
  backdrop-filter: blur(10px);
  border-right: 1px solid var(--line);
  padding: 1rem;
  overflow: auto;
}
.coach { border-right: 0; border-left: 1px solid var(--line); display: flex; flex-direction: column; }
.main { padding: 1.25rem 1.5rem 2rem; overflow: auto; }

h1, h2, h3 { font-family: var(--font-display); font-weight: 600; margin: 0 0 0.6rem; }
h1 { font-size: clamp(1.6rem, 2.4vw, 2.2rem); }
h2 { font-size: 1.25rem; }
.lead { font-size: 1.05rem; opacity: 0.85; max-width: 62ch; }

.nav-list { list-style: none; padding: 0; margin: 0.5rem 0 1rem; }
.nav-list li { margin: 0.25rem 0; }
.nav-list button {
  width: 100%;
  text-align: left;
  border: 1px solid transparent;
  background: transparent;
  padding: 0.55rem 0.65rem;
  border-radius: 10px;
  cursor: pointer;
  color: var(--ink);
}
.nav-list button:hover, .nav-list button.active {
  background: rgba(10, 77, 104, 0.08);
  border-color: rgba(10, 77, 104, 0.18);
}
.nav-list .status {
  float: right;
  font-size: 0.72rem;
  font-family: var(--font-mono);
  opacity: 0.7;
}
.status.mastered { color: var(--ok); }
.status.locked { color: #888; }
.status.in_progress { color: var(--warn); }

.card-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 1.1rem 1.2rem;
  box-shadow: var(--shadow);
  margin-bottom: 1rem;
}

.mastery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 0.75rem;
}
.mastery-tile {
  border-radius: 14px;
  padding: 0.9rem;
  background: linear-gradient(160deg, #fff, var(--foam));
  border: 1px solid var(--line);
}
.mastery-tile strong { display: block; margin-bottom: 0.35rem; }
.bar {
  height: 8px;
  background: rgba(0,0,0,0.08);
  border-radius: 999px;
  overflow: hidden;
}
.bar > i { display: block; height: 100%; background: var(--sea); width: 0; }

.sim-stage {
  position: relative;
  min-height: 360px;
  border-radius: 18px;
  background:
    linear-gradient(180deg, rgba(10,77,104,0.08), transparent 40%),
    repeating-linear-gradient(90deg, rgba(12,27,36,0.04) 0 1px, transparent 1px 28px),
    #f7fafc;
  border: 1px solid var(--line);
  padding: 1rem;
  overflow: hidden;
}
.sim-toolbar { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 0.85rem; }
.sim-hint { font-size: 0.92rem; opacity: 0.85; margin-bottom: 0.75rem; }

.jetty-row {
  display: flex;
  gap: 0.45rem;
  align-items: stretch;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}
.qrh-unit {
  min-width: 72px;
  padding: 0.65rem 0.4rem;
  border-radius: 12px;
  background: #fff;
  border: 2px solid var(--sea);
  text-align: center;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.qrh-unit:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.qrh-unit.selected { border-color: var(--accent); background: #fff5ef; }
.qrh-unit .tag { font-family: var(--font-mono); font-weight: 700; }
.qrh-unit .hooks { font-size: 0.78rem; opacity: 0.75; }
.platform {
  min-width: 56px;
  background: #d9d3c7;
  border: 2px dashed #8a8070;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  writing-mode: vertical-rl;
}

.box-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(120px, 1fr));
  gap: 0.75rem;
  max-width: 520px;
}
.box-card {
  border-radius: 14px;
  padding: 1rem;
  border: 2px solid var(--line);
  background: #fff;
  cursor: pointer;
  min-height: 110px;
}
.box-card.hab { border-color: #666; }
.box-card.ajb { border-color: #c45c26; }
.box-card.hcp { border-color: #0a4d68; }
.box-card.hcb { border-color: #1f7a4c; }
.box-card.correct { outline: 3px solid var(--ok); }
.box-card.wrong { outline: 3px solid var(--bad); }

.phase-rail {
  display: flex;
  gap: 0.5rem;
  margin: 1rem 0;
}
.phase-chip {
  flex: 1;
  text-align: center;
  padding: 0.7rem;
  border-radius: 12px;
  background: #fff;
  border: 2px solid var(--line);
  font-weight: 700;
  letter-spacing: 0.04em;
}
.phase-chip.active { border-color: var(--sea); background: var(--foam); }
.phase-chip.done { border-color: var(--ok); color: var(--ok); }
.speed-meter {
  height: 18px;
  border-radius: 999px;
  background: linear-gradient(90deg, #1f7a4c 0 40%, #b8860b 40% 70%, #a11d2e 70% 100%);
  position: relative;
  margin: 1rem 0;
}
.speed-needle {
  position: absolute;
  top: -6px;
  width: 4px;
  height: 30px;
  background: var(--ink);
  border-radius: 2px;
  transition: left 0.25s ease;
}

.mimic {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
  gap: 0.5rem;
}
.hook {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.55rem;
  text-align: center;
  cursor: pointer;
}
.hook.selected { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(196,92,38,0.25); }
.hook .padlock { font-size: 1.2rem; }
.hook .tons { font-family: var(--font-mono); font-size: 0.85rem; }
.hook.green .tons { color: var(--ok); }
.hook.yellow .tons { color: var(--warn); }
.hook.red .tons { color: var(--bad); }

.dual-buttons { display: flex; gap: 0.75rem; margin-top: 1rem; }
.big-btn {
  flex: 1;
  min-height: 64px;
  border-radius: 14px;
  border: 0;
  font-weight: 800;
  cursor: pointer;
  color: #fff;
  background: #8a1020;
  letter-spacing: 0.05em;
}
.big-btn.held, .big-btn:active { filter: brightness(1.15); transform: scale(0.98); }
.mode-toggle { display: inline-flex; gap: 0.35rem; margin: 0.5rem 0 1rem; }
.mode-toggle button {
  border: 1px solid var(--line);
  background: #fff;
  padding: 0.4rem 0.8rem;
  border-radius: 999px;
  cursor: pointer;
}
.mode-toggle button.on { background: var(--sea); color: #fff; border-color: var(--sea); }

.coach-log {
  flex: 1;
  overflow: auto;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  padding-right: 0.25rem;
  margin-bottom: 0.75rem;
}
.bubble {
  padding: 0.7rem 0.85rem;
  border-radius: 14px;
  max-width: 100%;
  white-space: pre-wrap;
  line-height: 1.4;
  font-size: 0.92rem;
}
.bubble.tutor { background: var(--foam); border: 1px solid rgba(10,77,104,0.15); }
.bubble.user { background: #fff; border: 1px solid var(--line); align-self: flex-end; }
.bubble .cite { display: block; margin-top: 0.4rem; font-size: 0.72rem; font-family: var(--font-mono); opacity: 0.65; }
.coach-compose { display: flex; gap: 0.4rem; }
.coach-compose input {
  flex: 1;
  border-radius: 10px;
  border: 1px solid var(--line);
  padding: 0.55rem 0.7rem;
  background: #fff;
}

.quiz-option {
  display: block;
  width: 100%;
  text-align: left;
  margin: 0.4rem 0;
  padding: 0.7rem 0.85rem;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: #fff;
  cursor: pointer;
}
.quiz-option.picked { border-color: var(--sea); background: var(--foam); }

.admin-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.feature-list label {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  padding: 0.25rem 0;
  font-size: 0.9rem;
}

@media (max-width: 1100px) {
  .app-shell { grid-template-columns: 1fr; grid-template-rows: auto auto 1fr auto; }
  .sidebar, .coach { border: 0; border-bottom: 1px solid var(--line); max-height: 280px; }
  .admin-grid { grid-template-columns: 1fr; }
}