/* assets/css/style.css */
/* ---------- Base reset ---------- */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;600&display=swap');

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
a { color: inherit; text-decoration: none; }

/* ---------- Color tokens ---------- */
:root{
  --bg: #0f1724;
  --panel: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  --text: #e6eef8;
  --muted: #9aa7bd;
  --accent: #7c5cff;
  --glass: rgba(255,255,255,0.03);
  --radius: 12px;
  --card-w: 320px;
  --shadow: 0 10px 30px rgba(2,6,23,0.6);
}

/* Light-mode override when .dark NOT present on root (we default to dark, but allow toggling) */
:root:not(.dark) {
  --bg: #f4f7fb;
  --panel: linear-gradient(180deg, rgba(255,255,255,0.8), rgba(255,255,255,0.7));
  --text: #0b1220;
  --muted: #55607a;
  --accent: #5b4eff;
  --glass: rgba(255,255,255,0.6);
  --shadow: 0 8px 22px rgba(2,6,23,0.08);
}

/* Dark mode when html has class "dark" */
html.dark {
  --bg: #071025;
  --panel: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  --text: #e6eef8;
  --muted: #9aa7bd;
  --accent: #7c5cff;
  --glass: rgba(255,255,255,0.03);
  --shadow: 0 12px 35px rgba(2,6,23,0.6);
}

/* ---------- Layout ---------- */
body {
  min-height: 100vh;
  font-family: 'Poppins', sans-serif;
  background: radial-gradient(1200px 600px at 10% 10%, rgba(124,92,255,0.07), transparent 8%),
              radial-gradient(900px 500px at 90% 90%, rgba(0,230,255,0.02), transparent 8%),
              var(--bg);
  color: var(--text);
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ---------- Header ---------- */
header {
  padding: 20px 20px;
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(6px);
  background: linear-gradient(180deg, rgba(0,0,0,0.02), rgba(0,0,0,0.02));
  border-bottom: 1px solid rgba(255,255,255,0.03);
}
header h1 {
  font-size: 1.7rem;
  letter-spacing: -0.5px;
  margin-bottom: 8px;
  text-align: center;
}

/* header controls */
.header-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  max-width: 1200px;
  margin: 0 auto;
}
.breadcrumb {
  font-size: 0.95rem;
  color: var(--muted);
}
.controls-right {
  display:flex;
  gap:12px;
  align-items:center;
}

/* Search */
.search-box { display:flex; align-items:center; }
.search-input {
  background: var(--glass);
  border: 1px solid rgba(255,255,255,0.03);
  padding: 10px 14px;
  border-radius: 999px;
  width: 260px;
  color: var(--text);
  outline: none;
  transition: transform .18s ease, box-shadow .18s ease;
  box-shadow: 0 2px 8px rgba(2,6,23,0.12);
}
.search-input::placeholder { color: var(--muted); }
.search-input:focus { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(2,6,23,0.12); }

/* Toggle */
.toggle-btn {
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  border: 1px solid rgba(255,255,255,0.04);
  padding: 8px 12px;
  border-radius: 999px;
  cursor: pointer;
  font-size: 1rem;
  transition: transform .18s ease, opacity .18s;
}
.toggle-btn:hover { transform: scale(1.04); }

/* ---------- Main ---------- */
main.container {
  flex: 1;
  padding: 28px;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

/* section title */
.section-title {
  margin: 8px 0 12px 6px;
  color: var(--muted);
  font-size: 0.95rem;
}

/* ---------- Cards grid ---------- */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, var(--card-w)), 1fr));
  gap: 18px;
  align-items: start;
}

/* ---------- Card base ---------- */
.card {
  background: var(--panel);
  border-radius: 14px;
  padding: 16px;
  border: 1px solid rgba(255,255,255,0.04);
  box-shadow: var(--shadow);
  transition: transform .28s cubic-bezier(.2,.9,.2,1), box-shadow .28s, opacity .28s;
  overflow: hidden;
  min-height: 120px;
  display: flex;
  align-items: stretch;
  animation: cardIn .45s ease both;
}
.card:hover { transform: translateY(-8px) scale(1.01); box-shadow: 0 22px 50px rgba(2,6,23,0.45); }
@keyframes cardIn {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* inner layout */
.card-inner { display:flex; gap:14px; width:100%; align-items:flex-start; }
.card .icon { width:72px; height:72px; flex-shrink:0; background-size:contain; background-repeat:no-repeat; background-position:center; border-radius:10px; }
.card .card-content { flex:1; display:flex; flex-direction:column; justify-content:center; }

/* Titles & meta */
.card-content h2, .card-content h3 { font-size:1.05rem; margin-bottom:6px; letter-spacing:-0.2px; }
.card-content .meta { color: var(--muted); font-size:0.88rem; margin-bottom:8px; }

/* action row */
.card-content .actions { margin-top: 8px; display:flex; gap:8px; flex-wrap:wrap; align-items:center; }

/* Buttons */
.download-btn, .youtube-btn, .view-btn {
  border: none;
  padding: 8px 12px;
  border-radius: 10px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  display:inline-flex;
  align-items:center;
  gap:8px;
  font-size:0.9rem;
}
.download-btn { background: linear-gradient(90deg,#ff7aa2,#e91e63); color:#fff; }
.youtube-btn { background: linear-gradient(90deg,#ff4b4b,#ff0000); color:#fff; }
.view-btn { background: rgba(255,255,255,0.04); color:var(--text); border:1px solid rgba(255,255,255,0.03); }

/* file-specific icons */
.pdf-icon { background-image: url('https://cdn-icons-png.flaticon.com/512/337/337946.png'); background-color: rgba(233,30,99,0.06); padding:12px; }
.video-icon { background-image: url('https://cdn-icons-png.flaticon.com/512/1384/1384060.png'); background-color: rgba(255,0,0,0.06); padding:12px; }
.folder-icon { background-image: url('https://cdn-icons-png.flaticon.com/512/715/715681.png'); background-color: rgba(92,79,255,0.06); padding:12px; }

/* thumbnail */
.thumb { width:120px; height:84px; object-fit:cover; border-radius:8px; margin-right:6px; }

/* tags */
.meta.tags { display:flex; gap:6px; flex-wrap:wrap; margin-top:6px; }
.meta.tags .tag { background: rgba(255,255,255,0.03); padding:6px 8px; border-radius:999px; color:var(--muted); font-size:0.78rem; }

/* important-topics card */
.important-topics {
  background: linear-gradient(180deg, rgba(0,0,0,0.12), rgba(255,255,255,0.02));
  border: 1px solid rgba(255,255,255,0.04);
  padding: 18px;
  border-radius: 14px;
  box-shadow: 0 10px 30px rgba(2,6,23,0.2);
}
.important-topics h3 {
  font-size:1.1rem;
  margin-bottom:10px;
  background: linear-gradient(90deg,#00d2ff,#3a7bd5);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* topic list */
.topic-list { list-style:none; padding-left:0; margin-top:8px; }
.topic-list li { padding:8px 0; color:var(--text); font-size:0.98rem; border-bottom: 1px dashed rgba(255,255,255,0.02); }
.topic-list li::before { content: "➤"; margin-right:8px; color:#00eaff; }

/* ---------- Modal ---------- */
.modal { position: fixed; inset: 0; display: grid; place-items: center; z-index: 120; pointer-events: none; opacity: 0; transition: opacity .22s ease; }
.modal.open { pointer-events: auto; opacity: 1; }
.modal-backdrop { position:absolute; inset:0; background: linear-gradient(180deg, rgba(0,0,0,0.55), rgba(0,0,0,0.6)); backdrop-filter: blur(4px); }
.modal-panel { position:relative; z-index: 130; width: min(1100px, 95%); max-height: 85vh; border-radius: 12px; overflow: hidden; box-shadow: 0 40px 120px rgba(2,6,23,0.6); }
.modal-body { background: #0a0f18; padding: 0; height: 75vh; display:flex; align-items:center; justify-content:center; }
.preview-frame { width:100%; height:100%; border:0; display:block; }
.modal-close { position:absolute; top:10px; right:10px; z-index: 200; border:none; background: rgba(255,255,255,0.04); color:var(--text); padding:8px 10px; border-radius:8px; cursor:pointer; }

/* video wrap */
.video-wrap { width:100%; height:100%; display:block; }

/* ---------- Footer ---------- */
footer { padding: 12px 20px; text-align:center; color:var(--muted); font-size:0.9rem; border-top:1px solid rgba(255,255,255,0.02); }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .search-input { width: 200px; }
  .card-inner { flex-direction: row; }
  .thumb { width: 100px; height: 64px; }
}
@media (max-width: 640px) {
  .header-controls { flex-direction: column; align-items: stretch; gap:8px; }
  .controls-right { justify-content: space-between; }
  .search-input { width: 100%; max-width: 100%; }
  .card { padding: 12px; }
  .card-inner { gap:10px; }
  .cards { gap:12px; }
}