/* IELTS Writing Study Site Styles */

:root {
  --bg: #0f0f14;
  --card: #1a1a24;
  --card-hover: #22222e;
  --border: #2a2a3a;
  --text: #e4e4ec;
  --text-dim: #8888a0;
  --accent: #f59e0b;
  --accent-dim: #b45309;
  --green: #22c55e;
  --blue: #3b82f6;
  --red: #ef4444;
  --purple: #a855f7;
  --radius: 12px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.6;
}

/* Header */
header {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
}

header h1 { font-size: 20px; font-weight: 700; display: flex; align-items: center; gap: 8px; }
header h1 span { color: var(--accent); }
header .stats { font-size: 13px; color: var(--text-dim); }

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

/* Volume Nav */
.volume-nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.volume-btn {
  padding: 10px 18px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  transition: all 0.2s;
}

.volume-btn:hover { background: var(--card-hover); border-color: var(--accent-dim); }
.volume-btn.active { background: var(--accent); color: #000; border-color: var(--accent); box-shadow: 0 4px 12px rgba(245, 158, 11, 0.2); }

/* Test Cards */
.test-grid { display: grid; gap: 16px; }

.test-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all 0.2s;
}

.test-card:hover { border-color: var(--accent-dim); box-shadow: 0 4px 20px rgba(0,0,0,0.3); }

.test-header {
  padding: 14px 20px;
  background: rgba(255,255,255,0.03);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.test-header h3 { font-size: 15px; font-weight: 600; }
.test-header .badge {
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 20px;
  font-weight: 600;
}
.badge-academic { background: rgba(59,130,246,0.15); color: var(--blue); }
.badge-general { background: rgba(168,85,247,0.15); color: var(--purple); }

.task-block {
  padding: 16px 20px;
  border-bottom: 1px solid rgba(255,255,255,0.04);
}

.task-block:last-child { border-bottom: none; }

.task-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--accent);
  margin-bottom: 6px;
}

.task-topic { font-size: 14px; color: var(--text); line-height: 1.5; }

.task-type {
  display: inline-block;
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 4px;
  background: rgba(255,255,255,0.06);
  color: var(--text-dim);
  margin-top: 6px;
}

/* Model Answer (collapsible) */
.answer-toggle {
  margin-top: 10px;
  background: none;
  border: 1px dashed var(--border);
  color: var(--accent);
  padding: 6px 14px;
  border-radius: 6px;
  font-size: 12px;
  cursor: pointer;
  transition: all 0.2s;
}

.answer-toggle:hover { border-color: var(--accent); background: rgba(245,158,11,0.08); }

.answer-content {
  display: none;
  margin-top: 12px;
  padding: 16px;
  background: rgba(0,0,0,0.2);
  border-radius: 8px;
  border-left: 3px solid var(--accent);
  font-size: 14px;
  line-height: 1.7;
  color: var(--text);
  white-space: pre-wrap;
  max-height: 500px;
  overflow-y: auto;
}

.answer-content.open { display: block; }

/* Empty state */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-dim);
}

.empty-state .icon { font-size: 48px; margin-bottom: 16px; }

/* Search */
.search-bar {
  margin-bottom: 20px;
}

.search-bar input {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card);
  color: var(--text);
  font-size: 14px;
  outline: none;
  transition: all 0.2s;
}

.search-bar input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(245,158,11,0.1); }
.search-bar input::placeholder { color: var(--text-dim); }

/* Filter tags */
.filter-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 12px;
  transition: all 0.2s;
}

.filter-btn:hover { border-color: var(--accent-dim); color: var(--text); }
.filter-btn.active { background: var(--accent); color: #000; border-color: var(--accent); }

/* Tab bar */
.tab-bar {
  display: flex;
  gap: 0;
  margin-bottom: 20px;
  background: var(--card);
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
}

.tab-btn {
  flex: 1;
  padding: 10px 16px;
  border: none;
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  transition: all 0.2s;
  border-bottom: 2px solid transparent;
}

.tab-btn:hover { color: var(--text); }
.tab-btn.active { color: var(--accent); border-bottom-color: var(--accent); background: rgba(245,158,11,0.06); }

/* Footer */
footer {
  text-align: center;
  padding: 40px 24px;
  color: var(--text-dim);
  font-size: 12px;
  border-top: 1px solid var(--border);
  margin-top: 40px;
}

/* Responsive */
@media (max-width: 600px) {
  .container { padding: 16px; }
  header { padding: 12px 16px; }
  header h1 { font-size: 16px; }
  .test-header { flex-direction: column; align-items: flex-start; gap: 6px; }
}