/* ── Theme ── */
:root {
  --bg-main: #16213e;
  --bg-sidebar: #0f0f1a;
  --bg-card: #1a1a2e;
  --border: #2a2a4a;
  --accent: #7b61ff;
  --accent-ml: #00b4d8;
  --text: #aaaaaa;
  --text-bright: #ffffff;
  --text-dim: #555555;
  --radius: 8px;
  --accent-dim: #7b61ff22;
  --accent-glow: #7b61ff44;
  --accent-ml-dim: #00b4d822;
  --bg-hover: #ffffff10;
  --bg-tag: #1e1e38;
  --accent-dim-hover: #7b61ff33;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; background: var(--bg-main); color: var(--text); min-height: 100vh; }
a { color: inherit; text-decoration: none; }

/* ── Layout ── */
.layout {
  display: flex;
  min-height: 100vh;
}

/* ── Sidebar ── */
.sidebar {
  width: 220px;
  flex-shrink: 0;
  background: var(--bg-sidebar);
  padding: 32px 20px;
  display: flex;
  flex-direction: column;
  gap: 32px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.name {
  font-size: 18px;
  font-weight: 800;
  color: var(--text-bright);
  letter-spacing: -0.5px;
}

.title {
  font-size: 12px;
  color: var(--text-dim);
  margin-top: 4px;
}

/* ── Filters ── */
.filters {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.filter-label {
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-dim);
  margin-bottom: 4px;
  font-weight: 600;
}

.filter-btn {
  background: none;
  border: none;
  color: var(--text);
  text-align: left;
  padding: 8px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  font-family: inherit;
  transition: background 0.15s, color 0.15s;
}

.filter-btn:hover {
  background: var(--bg-hover);
  color: var(--text-bright);
}

.filter-btn.active {
  background: var(--accent-dim);
  color: var(--accent);
  font-weight: 600;
}

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

/* ── Sidebar links ── */
.sidebar-links {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.sidebar-links a {
  color: var(--accent);
  font-size: 12px;
  transition: opacity 0.15s;
}

.sidebar-links a:hover { opacity: 0.7; }

/* ── Main ── */
.main {
  flex: 1;
  padding: 32px;
}

/* ── Cards grid ── */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

/* ── Card ── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.card:hover {
  border-color: var(--accent);
  box-shadow: 0 0 0 1px var(--accent-glow);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 8px;
}

.card-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-bright);
}

.badge {
  font-size: 10px;
  padding: 3px 8px;
  border-radius: 20px;
  white-space: nowrap;
  flex-shrink: 0;
}

.badge-robotics { background: var(--accent-dim); color: var(--accent); }
.badge-ml { background: var(--accent-ml-dim); color: var(--accent-ml); }

.card-desc {
  font-size: 12px;
  line-height: 1.6;
  color: var(--text);
  flex: 1;
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
}

.tags {
  display: flex;
  gap: 5px;
  flex-wrap: wrap;
}

.tag {
  font-size: 10px;
  padding: 2px 8px;
  border-radius: 4px;
  background: var(--bg-tag);
  color: var(--text);
}

.tag-accent { color: var(--accent); }
.tag-ml { color: var(--accent-ml); }

.card-link {
  font-size: 12px;
  color: var(--accent);
  white-space: nowrap;
  transition: opacity 0.15s;
}

.card-link:hover { opacity: 0.7; }

/* ── Hidden cards (filter) ── */
.card.hidden {
  display: none;
}

/* ── About ── */
.about {
  margin-top: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.about-label {
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-dim);
  font-weight: 600;
}

.about > p {
  font-size: 13px;
  line-height: 1.7;
}

/* ── Mobile ── */
@media (max-width: 700px) {
  .layout { flex-direction: column; }

  .sidebar {
    width: 100%;
    height: auto;
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    gap: 12px;
    padding: 16px;
  }

  .sidebar-top { flex: 1; min-width: 120px; }

  .filters {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 6px;
  }

  .filter-label { display: none; }

  .sidebar-links {
    flex-direction: row;
    margin-top: 0;
  }

  .main { padding: 16px; }

  .cards-grid { grid-template-columns: 1fr; }
}