/* ============================================
   BLACK SCREEN ENGLISH — Global Styles
   Dark Playground | White · Gold · Grey Palette
   ============================================ */

:root {
  --accent: #c9a84c;          /* gold */
  --accent-hover: #b8923d;
  --accent-2: #e8d5a3;        /* light gold */
  --accent-3: #f0f0f0;        /* near-white accent */
  --bg: #0a0a0a;              /* pure dark */
  --bg-card: #111111;         /* dark card */
  --bg-card-2: #181818;       /* slightly lighter dark */
  --border: #2a2a2a;          /* dark grey border */
  --text: #ffffff;            /* white */
  --text-muted: #a0a0a0;      /* grey */
  --text-dim: #555555;        /* dim grey */
  --gold: #c9a84c;
  --gold-light: #e8d5a3;
  --success: #7ab648;
  --warning: #c9a84c;
  --error: #c0392b;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.6);
  --shadow-gold: 0 4px 24px rgba(201, 168, 76, 0.2);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.7);
  --transition: 0.25s ease;
  --font: 'Inter', 'Segoe UI', system-ui, sans-serif;
}

[data-theme="light"] {
  --bg: #f7f5f0;
  --bg-card: #ffffff;
  --bg-card-2: #f0ece3;
  --border: #ddd8cc;
  --text: #111111;
  --text-muted: #555555;
  --text-dim: #999999;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.08);
}

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

html { scroll-behavior: smooth; font-size: 17px; }

/* ── Disable text selection & copying across the entire course ── */
* {
  -webkit-user-select: none;
  -moz-user-select: none;
  user-select: none;
}
/* Re-enable for input fields so students can still type & edit */
input, textarea, [contenteditable] {
  -webkit-user-select: text;
  -moz-user-select: text;
  user-select: text;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
  line-height: 1.6;
}

a { color: inherit; text-decoration: none; }

/* ── Scrollbar ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--accent); border-radius: 99px; }

/* ── Typography ── */
h1, h2, h3, h4 { font-weight: 700; letter-spacing: -0.02em; line-height: 1.2; }
h1 { font-size: clamp(2rem, 4vw, 3rem); }
h2 { font-size: clamp(1.4rem, 3vw, 2rem); }
h3 { font-size: clamp(1.1rem, 2vw, 1.4rem); }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: var(--font);
  transition: all var(--transition);
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-1px); box-shadow: 0 6px 20px rgba(201,168,76,0.4); }
.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 2px solid var(--accent);
}
.btn-outline:hover { background: var(--accent); color: #fff; }
.btn-ghost {
  background: var(--bg-card-2);
  color: var(--text-muted);
  border: 1px solid var(--border);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; }

/* ── Card ── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-card);
  transition: border-color var(--transition);
}
.card:hover { border-color: var(--accent); }

/* ── Badge ── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 12px;
  border-radius: 99px;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.badge-accent { background: rgba(201,168,76,0.12); color: var(--gold); border: 1px solid rgba(201,168,76,0.3); }
.badge-success { background: rgba(122,182,72,0.12); color: var(--success); border: 1px solid rgba(122,182,72,0.3); }
.badge-warning { background: rgba(201,168,76,0.12); color: var(--gold); border: 1px solid rgba(201,168,76,0.3); }

/* ── Progress Bar ── */
.progress-bar {
  height: 6px;
  background: var(--border);
  border-radius: 99px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  border-radius: 99px;
  transition: width 0.5s ease;
}

/* ── Gradient Text ── */
.gradient-text {
  background: linear-gradient(135deg, #c9a84c, #e8d5a3);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ── Utility ── */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: 8px; }
.gap-2 { gap: 16px; }
.gap-3 { gap: 24px; }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.w-full { width: 100%; }
.text-muted { color: var(--text-muted); }
.text-sm { font-size: 0.875rem; }
.text-center { text-align: center; }