/* ── Reset & Variables ────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary: #25D366;
  --primary-dark: #128C7E;
  --danger: #e74c3c;
  --danger-dark: #c0392b;
  --bg: #0d1117;
  --surface: #161b22;
  --surface2: #21262d;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --radius: 10px;
  --shadow: 0 4px 16px rgba(0,0,0,.4);
}

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

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Utility ──────────────────────────────────────────────────── */
.center-page {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 1rem;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 1.25rem;
}

.text-center { text-align: center; }
.text-muted { color: var(--text-muted); font-size: .9rem; }
.text-danger { color: var(--danger); }
.hidden { display: none !important; }

/* ── Card ─────────────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: var(--shadow);
}

.section-card h3 {
  font-size: 1.05rem;
  margin-bottom: .75rem;
}

/* ── Navbar ───────────────────────────────────────────────────── */
.navbar {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: .85rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-brand {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: .5px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-link {
  color: var(--text-muted);
  font-size: .9rem;
  transition: color .2s;
}
.nav-link:hover { color: var(--text); text-decoration: none; }

/* ── Buttons ──────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .55rem 1.2rem;
  border-radius: 7px;
  font-size: .9rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: background .2s, opacity .2s;
}
.btn:disabled { opacity: .55; cursor: not-allowed; }

.btn-primary { background: var(--primary); color: #000; }
.btn-primary:hover { background: var(--primary-dark); color: #fff; }

.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { background: var(--danger-dark); }

.btn-outline {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
}
.btn-outline:hover { background: var(--surface2); }

.btn-sm { padding: .35rem .8rem; font-size: .82rem; }
.btn-full { width: 100%; justify-content: center; }
.btn-group { display: flex; gap: .5rem; }

/* ── Forms ────────────────────────────────────────────────────── */
.form-group { margin-bottom: 1.1rem; }
.form-group label {
  display: block;
  margin-bottom: .45rem;
  font-size: .88rem;
  font-weight: 600;
  color: var(--text-muted);
}

input[type=text], input[type=email], input[type=password],
input[type=number], input[type=time], input[type=file],
textarea, .select-input {
  width: 100%;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 7px;
  color: var(--text);
  padding: .65rem .9rem;
  font-size: .9rem;
  outline: none;
  transition: border-color .2s;
  font-family: inherit;
}
input:focus, textarea:focus, .select-input:focus { border-color: var(--primary); }
textarea { resize: vertical; }

.inline-form {
  display: flex;
  align-items: center;
  gap: .75rem;
  flex-wrap: wrap;
}
.inline-form input { width: auto; }

.search-input {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 7px;
  color: var(--text);
  padding: .65rem .9rem;
  width: 100%;
  font-size: .9rem;
  outline: none;
}
.search-input:focus { border-color: var(--primary); }

/* ── Login Card ───────────────────────────────────────────────── */
.login-card { width: 100%; max-width: 400px; }
.brand { text-align: center; margin-bottom: 2rem; }
.brand-icon { font-size: 3rem; display: block; margin-bottom: .5rem; }
.brand h1 { font-size: 1.8rem; }
.brand .subtitle { color: var(--text-muted); }

/* ── Alert ────────────────────────────────────────────────────── */
.alert {
  padding: .75rem 1rem;
  border-radius: 7px;
  margin-bottom: 1.25rem;
  font-size: .9rem;
}
.alert-error { background: rgba(231,76,60,.15); border: 1px solid var(--danger); color: #ff8a7a; }

/* ── QR ───────────────────────────────────────────────────────── */
.qr-wrap { margin: 1.5rem auto; display: flex; justify-content: center; }
.qr-wrap img { border-radius: var(--radius); border: 4px solid var(--primary); width: 240px; height: 240px; }

/* ── Spinner ──────────────────────────────────────────────────── */
.spinner {
  width: 48px; height: 48px;
  border: 4px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin .8s linear infinite;
  margin: 0 auto;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Page Header ──────────────────────────────────────────────── */
.page-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.75rem;
  flex-wrap: wrap;
}
.page-header h2 { font-size: 1.4rem; }

/* ── Group Grid ───────────────────────────────────────────────── */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  flex-wrap: wrap;
  gap: .5rem;
}

.group-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: .6rem;
  max-height: 480px;
  overflow-y: auto;
  padding-right: .25rem;
}

.group-item {
  display: flex;
  align-items: center;
  gap: .55rem;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: .7rem .9rem;
  cursor: pointer;
  user-select: none;
  transition: border-color .15s, background .15s;
  position: relative;
}
.group-item input[type=checkbox] { display: none; }
.group-item:hover { border-color: var(--primary); }
.group-item.checked { border-color: var(--primary); background: rgba(37,211,102,.08); }

.group-icon { font-size: 1.1rem; flex-shrink: 0; }
.group-name { font-size: .85rem; flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.checkmark { color: var(--primary); font-weight: 800; opacity: 0; transition: opacity .15s; }
.group-item.checked .checkmark { opacity: 1; }

.selected-count {
  margin-top: 1rem;
  font-size: .9rem;
  color: var(--primary);
  font-weight: 600;
}

/* ── Tabs ─────────────────────────────────────────────────────── */
.tabs {
  display: flex;
  gap: .4rem;
  flex-wrap: wrap;
  margin-bottom: 1.25rem;
}

.tab-btn {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 7px;
  color: var(--text-muted);
  padding: .5rem 1rem;
  font-size: .85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all .15s;
}
.tab-btn:hover { border-color: var(--primary); color: var(--text); }
.tab-btn.active { background: var(--primary); border-color: var(--primary); color: #000; }

.tab-content { display: block; }
.tab-content.hidden { display: none; }

/* ── Badges ───────────────────────────────────────────────────── */
.badge {
  display: inline-block;
  padding: .15rem .5rem;
  border-radius: 4px;
  font-size: .75rem;
  font-weight: 600;
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text-muted);
}
.badge-info { background: rgba(37,211,102,.12); border-color: var(--primary); color: var(--primary); }

/* ── Schedule Items ───────────────────────────────────────────── */
.schedule-item {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding: .9rem;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: .6rem;
}

/* ── Toast ────────────────────────────────────────────────────── */
.toast {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  padding: .8rem 1.4rem;
  border-radius: 8px;
  font-size: .9rem;
  font-weight: 600;
  z-index: 9999;
  animation: slideUp .25s ease;
  max-width: 340px;
}
.toast-ok { background: var(--primary); color: #000; }
.toast-err { background: var(--danger); color: #fff; }
@keyframes slideUp { from { transform: translateY(12px); opacity: 0; } to { opacity: 1; } }

/* ── Result Box ───────────────────────────────────────────────── */
.result-box {
  margin-top: 1.25rem;
  padding: 1rem;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: .87rem;
}
.result-box ul { list-style: none; padding: 0; margin-top: .5rem; }
.result-box li { padding: .2rem 0; }

/* ── Group Chips ──────────────────────────────────────────────── */
.group-chips { display: flex; flex-wrap: wrap; gap: .5rem; }
.chip {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: .25rem .75rem;
  font-size: .82rem;
  color: var(--text-muted);
}
.chip-admin { border-color: var(--primary); color: var(--primary); }

/* ── Toggle label ─────────────────────────────────────────────── */
.toggle-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

/* ── Scrollbar ────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ── Responsive ───────────────────────────────────────────────── */
@media (max-width: 600px) {
  .container { padding: 1rem .85rem; }
  .group-grid { grid-template-columns: 1fr 1fr; }
  .tabs { gap: .25rem; }
  .tab-btn { padding: .4rem .7rem; font-size: .78rem; }
}