:root {
  --bg: #0f1419;
  --surface: #1a222c;
  --border: rgba(148, 163, 184, 0.18);
  --text: #e8eef4;
  --muted: #94a3b8;
  --accent: #14b8a6;
  --accent-dim: rgba(20, 184, 166, 0.14);
  --danger: #f87171;
  --font: "Segoe UI", "Helvetica Neue", sans-serif;
  --display: Georgia, "Times New Roman", serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  font-family: var(--font);
  color: var(--text);
  background:
    radial-gradient(ellipse 90% 60% at 10% -10%, rgba(20, 184, 166, 0.18), transparent 55%),
    radial-gradient(ellipse 70% 50% at 100% 0%, rgba(56, 189, 248, 0.08), transparent 50%),
    var(--bg);
}

a { color: var(--accent); }

#app {
  max-width: 920px;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}

.shell-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.75rem;
}

.shell-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem 0.85rem;
  justify-content: flex-end;
}

.nav-link {
  color: var(--text);
  text-decoration: none;
  font-size: 0.92rem;
  border-bottom: 1px solid transparent;
}

.nav-link:hover {
  border-bottom-color: var(--accent);
  color: var(--accent);
}

.brand {
  font-family: var(--display);
  font-size: 1.65rem;
  letter-spacing: -0.03em;
  margin: 0;
}

.brand-sub {
  margin: 0.35rem 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem 1.35rem;
}

.login-card {
  max-width: 400px;
  margin: 3rem auto 0;
}

label {
  display: block;
  margin: 0.85rem 0 0.35rem;
  font-size: 0.85rem;
  color: var(--muted);
}

input {
  width: 100%;
  padding: 0.7rem 0.8rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #10161d;
  color: var(--text);
  font: inherit;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 0.55rem 0.9rem;
  font: inherit;
  font-size: 0.9rem;
  cursor: pointer;
  text-decoration: none;
  color: var(--text);
  background: transparent;
}

.btn-primary {
  background: var(--accent);
  color: #042f2e;
  font-weight: 600;
  margin-top: 1rem;
  width: 100%;
}

.btn-ghost {
  border-color: var(--border);
  color: var(--muted);
}

.btn-sm {
  padding: 0.35rem 0.65rem;
  font-size: 0.8rem;
}

.error {
  color: var(--danger);
  font-size: 0.9rem;
  margin: 0.75rem 0 0;
}

.muted { color: var(--muted); font-size: 0.9rem; }

.room-list {
  display: grid;
  gap: 0.75rem;
  margin-top: 1rem;
}

.room-card {
  display: block;
  text-decoration: none;
  color: inherit;
  padding: 1rem 1.1rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(20, 184, 166, 0.08), transparent 70%), var(--surface);
  transition: border-color 0.15s ease;
}

.room-card:hover { border-color: rgba(20, 184, 166, 0.45); }

.room-card h2 {
  margin: 0 0 0.35rem;
  font-size: 1.1rem;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  margin: 0 0 1rem;
}

.file-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

.file-table th,
.file-table td {
  text-align: left;
  padding: 0.65rem 0.4rem;
  border-bottom: 1px solid var(--border);
}

.file-table th {
  color: var(--muted);
  font-weight: 500;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.file-name-btn {
  background: none;
  border: none;
  padding: 0;
  color: var(--text);
  font: inherit;
  cursor: pointer;
  text-align: left;
}

.file-name-btn:hover { color: var(--accent); }

.folder-icon { color: var(--accent); }

.empty {
  padding: 1.5rem 0;
  color: var(--muted);
  text-align: center;
}