:root {
  --bg: #0a0e14;
  --bg-alt: #0f1620;
  --panel: #121a24;
  --panel-border: #1f2c3a;
  --green: #3ddc84;
  --green-dim: #2a9d5c;
  --cyan: #4fd1ff;
  --yellow: #f5c542;
  --red: #ff5c5c;
  --purple: #b57bff;
  --text: #d6e2ea;
  --text-dim: #7e94a3;
  --mono: 'Courier New', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: radial-gradient(circle at top, #0d141d 0%, var(--bg) 60%);
  color: var(--text);
  font-family: var(--sans);
  min-height: 100vh;
}

a { color: var(--cyan); text-decoration: none; }

code {
  font-family: var(--mono);
  background: #0d1520;
  border: 1px solid var(--panel-border);
  padding: 1px 6px;
  border-radius: 4px;
  color: var(--green);
  font-size: 0.92em;
}

.note { color: var(--yellow); font-size: 0.9em; }

/* ---------------- Top bar ---------------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 28px;
  border-bottom: 1px solid var(--panel-border);
  background: rgba(10, 14, 20, 0.85);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(6px);
  flex-wrap: wrap;
  gap: 10px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--green);
}
.brand .dot { width: 10px; height: 10px; border-radius: 50%; background: var(--green); box-shadow: 0 0 10px var(--green); }

.stats-strip {
  display: flex;
  gap: 18px;
  align-items: center;
  font-family: var(--mono);
  font-size: 0.88rem;
  color: var(--text-dim);
}
.stats-strip strong { color: var(--text); }
.rank-pill {
  background: linear-gradient(90deg, rgba(61,220,132,0.15), rgba(79,209,255,0.15));
  border: 1px solid var(--green-dim);
  padding: 3px 10px;
  border-radius: 20px;
  color: var(--green);
  font-weight: 600;
}

.btn {
  font-family: var(--sans);
  background: var(--panel);
  border: 1px solid var(--panel-border);
  color: var(--text);
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.15s ease;
}
.btn:hover { border-color: var(--cyan); color: var(--cyan); }
.btn.primary { background: var(--green); color: #06130a; border-color: var(--green); font-weight: 700; }
.btn.primary:hover { background: #4ff099; color: #06130a; }
.btn.danger:hover { border-color: var(--red); color: var(--red); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }
.btn.ghost { background: transparent; }

/* ---------------- Dashboard ---------------- */
.container { max-width: 1100px; margin: 0 auto; padding: 30px 24px 80px; }

.hero {
  text-align: center;
  padding: 36px 10px 26px;
}
.hero h1 {
  font-family: var(--mono);
  font-size: 2.1rem;
  margin: 0 0 8px;
  background: linear-gradient(90deg, var(--green), var(--cyan));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero p { color: var(--text-dim); max-width: 620px; margin: 0 auto; }

.progress-overview {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 14px;
  margin: 26px 0 36px;
}
.stat-card {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  padding: 16px 18px;
  text-align: center;
}
.stat-card .big { font-family: var(--mono); font-size: 1.8rem; font-weight: 700; color: var(--green); }
.stat-card .label { color: var(--text-dim); font-size: 0.8rem; margin-top: 4px; text-transform: uppercase; letter-spacing: 0.04em; }

.overall-bar {
  height: 10px;
  background: #0d1520;
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--panel-border);
  margin-top: 10px;
}
.overall-bar > div { height: 100%; background: linear-gradient(90deg, var(--green), var(--cyan)); transition: width 0.4s ease; }

.room-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 18px;
}

.room-card {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 14px;
  padding: 20px;
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  cursor: pointer;
  transition: transform 0.15s ease, border-color 0.15s ease;
}
.room-card:hover:not(.locked) { transform: translateY(-3px); border-color: var(--cyan); }
.room-card.locked { cursor: not-allowed; opacity: 0.55; }
.room-card .top-row { display: flex; justify-content: space-between; align-items: flex-start; }
.room-card .icon { font-size: 1.8rem; }
.room-card h3 { margin: 0; font-size: 1.08rem; }
.room-card p.blurb { color: var(--text-dim); font-size: 0.86rem; margin: 0; flex: 1; }

.badge {
  font-size: 0.72rem;
  padding: 3px 10px;
  border-radius: 20px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  white-space: nowrap;
}
.badge.Easy { background: rgba(61,220,132,0.15); color: var(--green); border: 1px solid var(--green-dim); }
.badge.Medium { background: rgba(245,197,66,0.15); color: var(--yellow); border: 1px solid #a68122; }
.badge.Hard { background: rgba(255,92,92,0.15); color: var(--red); border: 1px solid #a33; }
.badge.VeryHard { background: rgba(255,92,92,0.2); color: var(--red); border: 1px solid #a33; }
.badge.Boss { background: rgba(181,123,255,0.18); color: var(--purple); border: 1px solid #7a4fc7; }

.room-card .bar { height: 7px; background: #0d1520; border-radius: 5px; overflow: hidden; border: 1px solid var(--panel-border); }
.room-card .bar > div { height: 100%; background: linear-gradient(90deg, var(--green), var(--cyan)); }
.room-card .meta-row { display: flex; justify-content: space-between; font-size: 0.78rem; color: var(--text-dim); font-family: var(--mono); }

.lock-overlay {
  position: absolute; inset: 0; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(10,14,20,0.55); font-size: 1.6rem;
}

/* ---------------- Room page ---------------- */
.room-layout { display: grid; grid-template-columns: 240px 1fr; gap: 24px; align-items: flex-start; }
@media (max-width: 800px) { .room-layout { grid-template-columns: 1fr; } }

.task-nav { background: var(--panel); border: 1px solid var(--panel-border); border-radius: 12px; padding: 14px; position: sticky; top: 90px; }
.task-nav h4 { margin: 2px 0 10px; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-dim); }
.task-nav .task-item {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 10px; border-radius: 8px; font-size: 0.85rem; cursor: pointer; color: var(--text-dim);
}
.task-nav .task-item.active { background: rgba(79,209,255,0.1); color: var(--cyan); }
.task-nav .task-item.done { color: var(--green); }
.task-nav .check { width: 16px; display: inline-block; text-align: center; }

.task-panel { background: var(--panel); border: 1px solid var(--panel-border); border-radius: 14px; padding: 26px 28px; min-height: 300px; }
.task-panel h2 { margin-top: 0; font-family: var(--mono); color: var(--cyan); }
.theory p { line-height: 1.6; color: var(--text); }
.theory ul { line-height: 1.6; color: var(--text); }
.theory li { margin-bottom: 4px; }

.terminal {
  background: #060a0f;
  border: 1px solid #1c2733;
  border-radius: 10px;
  margin: 18px 0;
  overflow: hidden;
  box-shadow: 0 0 0 1px rgba(61,220,132,0.05) inset;
}
.terminal .term-bar {
  display: flex; gap: 6px; align-items: center;
  padding: 8px 12px; background: #0b121a; border-bottom: 1px solid #1c2733;
}
.terminal .term-bar span { width: 11px; height: 11px; border-radius: 50%; display: inline-block; }
.terminal .term-bar .r { background: #ff5f56; } .terminal .term-bar .y { background: #ffbd2e; } .terminal .term-bar .g { background: #27c93f; }
.terminal .term-title { margin-left: 10px; color: var(--text-dim); font-family: var(--mono); font-size: 0.78rem; }
.terminal pre {
  margin: 0; padding: 16px 18px; font-family: var(--mono); font-size: 0.86rem; line-height: 1.55;
  color: var(--green); white-space: pre-wrap; word-break: break-word; max-height: 420px; overflow-y: auto;
}
.terminal .cmdline { color: var(--cyan); }
.terminal .prompt { color: var(--text-dim); }

.question-block {
  border-top: 1px solid var(--panel-border);
  padding-top: 18px;
  margin-top: 18px;
}
.question-block .q-points { color: var(--yellow); font-family: var(--mono); font-size: 0.78rem; float: right; }
.question-block .q-prompt { font-weight: 600; margin-bottom: 10px; }

.flag-row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.flag-row input[type=text] {
  flex: 1; min-width: 200px; background: #060a0f; border: 1px solid var(--panel-border); color: var(--green);
  font-family: var(--mono); padding: 10px 12px; border-radius: 8px; font-size: 0.95rem;
}
.flag-row input[type=text]:focus { outline: none; border-color: var(--cyan); }
.flag-row input[type=text].correct { border-color: var(--green); background: rgba(61,220,132,0.08); }
.flag-row input[type=text].wrong { border-color: var(--red); animation: shake 0.3s; }

.mcq-options { display: flex; flex-direction: column; gap: 8px; margin-top: 4px; }
.mcq-option {
  border: 1px solid var(--panel-border); border-radius: 8px; padding: 10px 14px; cursor: pointer;
  background: #0d1520; font-size: 0.92rem; transition: border-color 0.12s ease;
}
.mcq-option:hover { border-color: var(--cyan); }
.mcq-option.selected { border-color: var(--cyan); background: rgba(79,209,255,0.08); }
.mcq-option.correct { border-color: var(--green); background: rgba(61,220,132,0.12); }
.mcq-option.wrong { border-color: var(--red); background: rgba(255,92,92,0.1); }

@keyframes shake { 0%,100% { transform: translateX(0); } 25% { transform: translateX(-6px); } 75% { transform: translateX(6px); } }

.feedback { margin-top: 10px; font-size: 0.86rem; font-family: var(--mono); min-height: 1.2em; }
.feedback.ok { color: var(--green); }
.feedback.bad { color: var(--red); }

.q-actions { margin-top: 10px; display: flex; gap: 10px; align-items: center; }
.hint-text { color: var(--yellow); font-size: 0.82rem; margin-top: 6px; }

.task-footer { display: flex; justify-content: space-between; margin-top: 26px; }

.room-complete {
  text-align: center; padding: 50px 20px;
}
.room-complete .big-icon { font-size: 3.4rem; }
.room-complete h2 { font-family: var(--mono); color: var(--green); }

.toast {
  position: fixed; bottom: 24px; right: 24px; background: var(--panel); border: 1px solid var(--green-dim);
  color: var(--green); padding: 12px 18px; border-radius: 10px; font-family: var(--mono); font-size: 0.85rem;
  box-shadow: 0 6px 20px rgba(0,0,0,0.4); z-index: 50; animation: toastIn 0.25s ease;
}
@keyframes toastIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

footer.site-footer { text-align: center; color: var(--text-dim); font-size: 0.8rem; padding: 30px 0; }