/* ── Tokens ─────────────────────────────────────────────── */
:root {
  --bg:         #0f1117;
  --surface:    #181c25;
  --surface-2:  #1f2535;
  --border:     #2a3044;
  --border-2:   #3a4460;
  --accent:     #4f8ef7;
  --accent-dim: rgba(79,142,247,0.12);
  --success:    #34c97a;
  --danger:     #f75a5a;
  --warn:       #f0a830;
  --text-1:     #e8eaf2;
  --text-2:     #8b90a8;
  --text-3:     #555c78;
  --radius:     10px;
  --radius-sm:  6px;
  --mono:       'DM Mono', monospace;
  --sans:       'DM Sans', sans-serif;
}

/* ── Reset ──────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 15px; }
body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text-1);
  min-height: 100vh;
  line-height: 1.6;
}
a { color: inherit; text-decoration: none; }
input, textarea, button, select { font-family: inherit; font-size: inherit; }
input, textarea, select {
  background: var(--surface);
  border: 1.5px solid var(--border);
  color: var(--text-1);
  border-radius: var(--radius-sm);
  padding: 0.55rem 0.75rem;
  width: 100%;
  outline: none;
  transition: border-color 0.15s;
}
input:focus, textarea:focus, select:focus { border-color: var(--accent); }
textarea { resize: vertical; }

/* New-class: weekly recurrence fields */
.weekly-fields { display: flex; align-items: center; gap: 0.6rem; }
.weekly-fields input[type="number"] { flex: 1; }
.weekly-fields input[type="date"] { flex: 1; }
.weekly-or { color: var(--text-3); font-size: 0.8rem; white-space: nowrap; }

/* Weekly series badge on a class card title */
.series-badge { margin-left: 0.5rem; vertical-align: middle; }

/* Registration deadline meta — emphasised once closed */
.meta-closed { color: var(--danger, #e5564b); }

/* ── Header ─────────────────────────────────────────────── */
.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 50;
}
.header-inner {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 1.25rem;
  height: 54px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 1rem;
}
.logo-mark {
  color: var(--accent);
  font-size: 1.1rem;
  line-height: 1;
}
.logo-badge {
  font-size: 0.7rem;
  font-family: var(--mono);
  background: var(--accent-dim);
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 1px 7px;
  border-radius: 20px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.header-actions { display: flex; align-items: center; gap: 0.75rem; }
.admin-link {
  font-size: 0.85rem;
  color: var(--text-2);
  transition: color 0.15s;
}
.admin-link:hover { color: var(--text-1); }

/* ── Layout ─────────────────────────────────────────────── */
.main-content {
  max-width: 860px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
}
.page-intro { margin-bottom: 2rem; }
.page-intro h1 { font-size: 1.5rem; font-weight: 600; }
.page-intro p { color: var(--text-2); margin-top: 0.25rem; }

/* ── Buttons ─────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1.1rem;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  font-weight: 500;
  font-size: 0.875rem;
  transition: opacity 0.15s, background 0.15s;
  white-space: nowrap;
}
.btn:hover { opacity: 0.88; }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }
.btn-primary   { background: var(--accent); color: #fff; }
.btn-secondary { background: var(--surface-2); color: var(--text-1); border: 1.5px solid var(--border-2); }
.btn-danger    { background: var(--danger); color: #fff; }
.btn-ghost     { background: transparent; color: var(--text-2); border: 1.5px solid var(--border); }
.btn-sm        { padding: 0.3rem 0.75rem; font-size: 0.8rem; }
.btn-row       { display: flex; gap: 0.75rem; flex-wrap: wrap; }

/* ── Class Cards ─────────────────────────────────────────── */
.schedule-list { display: flex; flex-direction: column; gap: 1rem; }

.class-card {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.15s;
}
.class-card:hover { border-color: var(--border-2); }

.class-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: 1rem 1.25rem 0.75rem;
  gap: 1rem;
}
.class-card-title { font-size: 1rem; font-weight: 600; }
.class-card-meta {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
  margin-top: 0.2rem;
}
.meta-item {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.8rem;
  color: var(--text-2);
  font-family: var(--mono);
}
.meta-icon { font-size: 0.75rem; }

.seat-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.75rem;
  font-family: var(--mono);
  font-weight: 500;
  padding: 0.25rem 0.6rem;
  border-radius: 20px;
  white-space: nowrap;
  flex-shrink: 0;
}
.seat-badge.open   { background: rgba(52,201,122,0.12); color: var(--success); border: 1px solid rgba(52,201,122,0.3); }
.seat-badge.few    { background: rgba(240,168,48,0.12);  color: var(--warn);    border: 1px solid rgba(240,168,48,0.3); }
.seat-badge.full   { background: rgba(247,90,90,0.10);   color: var(--danger);  border: 1px solid rgba(247,90,90,0.3); }

.class-card-body {
  border-top: 1px solid var(--border);
  padding: 0.75rem 1.25rem;
}
.class-card-footer {
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

/* Roster list */
.roster { display: flex; flex-direction: column; gap: 0.35rem; }
.roster-title {
  font-size: 0.7rem;
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-3);
  margin-bottom: 0.4rem;
}
.roster-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.35rem 0.65rem;
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  font-size: 0.85rem;
  gap: 0.5rem;
}
.roster-item.is-absent {
  opacity: 0.55;
}
.roster-name { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.roster-tag {
  font-size: 0.68rem;
  font-family: var(--mono);
  padding: 1px 6px;
  border-radius: 4px;
  flex-shrink: 0;
}
.tag-core    { background: var(--accent-dim); color: var(--accent); }
.tag-absent  { background: rgba(247,90,90,0.1); color: var(--danger); }
.tag-note    { color: var(--text-3); font-size: 0.75rem; flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; }
.roster-actions { display: flex; gap: 0.4rem; align-items: center; flex-shrink: 0; }

/* ── Admin toolbar ───────────────────────────────────────── */
.admin-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 2rem;
  gap: 1rem;
  flex-wrap: wrap;
}
.admin-toolbar h1 { font-size: 1.5rem; font-weight: 600; }
.toolbar-actions { display: flex; gap: 0.75rem; }
.admin-card-actions { display: flex; gap: 0.5rem; }

/* ── Modals ──────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.65);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 1rem;
  backdrop-filter: blur(2px);
}
.modal {
  background: var(--surface);
  border: 1.5px solid var(--border-2);
  border-radius: var(--radius);
  padding: 1.75rem;
  width: 100%;
  max-width: 420px;
  position: relative;
}
.modal-wide { max-width: 560px; }
.modal h2 { font-size: 1.1rem; font-weight: 600; margin-bottom: 0.35rem; }
.modal-meta { color: var(--text-2); font-size: 0.85rem; margin-bottom: 1.25rem; }
.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  color: var(--text-3);
  cursor: pointer;
  font-size: 0.9rem;
  padding: 0.25rem 0.4rem;
  border-radius: 4px;
  transition: color 0.15s;
}
.modal-close:hover { color: var(--text-1); }

/* ── Forms ───────────────────────────────────────────────── */
.form-group { display: flex; flex-direction: column; gap: 0.35rem; margin-bottom: 1rem; }
.form-group label { font-size: 0.825rem; color: var(--text-2); font-weight: 500; }
.label-hint { font-weight: 400; color: var(--text-3); }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0 1rem; }
.form-span-2 { grid-column: span 2; }
.form-error { color: var(--danger); font-size: 0.82rem; margin-top: 0.5rem; }
.delete-warning { color: var(--text-2); font-size: 0.85rem; margin-bottom: 1.25rem; }

/* ── Login wall ──────────────────────────────────────────── */
.login-wall {
  min-height: calc(100vh - 54px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 1rem;
}
.login-card {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
  width: 100%;
  max-width: 360px;
  text-align: center;
}
.login-icon {
  font-size: 2rem;
  color: var(--accent);
  margin-bottom: 1rem;
}
.login-card h1 { font-size: 1.25rem; font-weight: 600; margin-bottom: 0.4rem; }
.login-card p { color: var(--text-2); font-size: 0.875rem; margin-bottom: 1.5rem; }
.login-card .form-group { text-align: left; }
.login-card .btn { width: 100%; justify-content: center; margin-top: 0.25rem; }

/* ── States ──────────────────────────────────────────────── */
.hidden { display: none !important; }
.loading-state, .empty-state {
  text-align: center;
  color: var(--text-3);
  padding: 3rem 1rem;
  font-size: 0.9rem;
}
.empty-state strong { display: block; color: var(--text-2); margin-bottom: 0.35rem; font-size: 1rem; }

/* ── Toast ───────────────────────────────────────────────── */
#toast {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%) translateY(12px);
  background: var(--surface-2);
  border: 1.5px solid var(--border-2);
  color: var(--text-1);
  padding: 0.6rem 1.25rem;
  border-radius: 20px;
  font-size: 0.85rem;
  opacity: 0;
  transition: opacity 0.2s, transform 0.2s;
  z-index: 999;
  pointer-events: none;
  white-space: nowrap;
}
#toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ── Mobile ──────────────────────────────────────────────── */
@media (max-width: 600px) {
  .form-grid { grid-template-columns: 1fr; }
  .form-span-2 { grid-column: span 1; }
  .class-card-footer { flex-direction: column; align-items: flex-start; }
  .admin-toolbar { flex-direction: column; align-items: flex-start; }
}