/* ============================================================
   HPIS Examination Management System – Main Stylesheet
   ============================================================ */

/* ─── CSS Variables ──────────────────────────────────────── */
:root {
  --sidebar-width: 260px;
  --sidebar-bg: #1a237e;
  --sidebar-text: rgba(255, 255, 255, 0.85);
  --sidebar-active-bg: rgba(255,255,255,.15);
  --sidebar-hover-bg: rgba(255,255,255,.08);
  --navbar-height: 56px;
  --content-bg: #f0f2f5;
  --card-radius: 12px;
  --primary: #1565c0;
  --success: #2e7d32;
  --warning: #f57f17;
  --danger: #c62828;
  --info: #0277bd;
  --transition: all .2s ease;
}

[data-bs-theme="dark"] {
  --sidebar-bg: #0d1117;
  --content-bg: #161b22;
  --sidebar-text: rgba(255,255,255,.8);
}

/* ─── Base ───────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--content-bg);
  margin: 0;
  font-size: 14px;
  overflow-x: hidden;
}

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

.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  display: flex;
  flex-direction: column;
  transition: margin-left .3s ease;
  min-width: 0;
}

.content-area {
  flex: 1;
  padding: 1.5rem;
  overflow-x: hidden;
}

/* ─── Sidebar ────────────────────────────────────────────── */
.sidebar {
  width: var(--sidebar-width);
  background: var(--sidebar-bg);
  height: 100vh;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1040;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  transition: transform .3s ease;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,.2) transparent;
}

.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-thumb { background: rgba(255,255,255,.2); border-radius: 2px; }

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: .75rem;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid rgba(255,255,255,.1);
  color: #fff;
  text-decoration: none;
}

.sidebar-logo {
  width: 40px;
  height: 40px;
  object-fit: contain;
  border-radius: 8px;
  background: rgba(255,255,255,.15);
  padding: 4px;
}

.sidebar-brand-text span { font-size: .9rem; color: #fff; }
.sidebar-brand-text small { font-size: .7rem; }

.sidebar-user {
  padding: .75rem 1.25rem;
  border-bottom: 1px solid rgba(255,255,255,.1);
  color: var(--sidebar-text);
}

.user-avatar { color: rgba(255,255,255,.7); }

.sidebar-divider {
  border-color: rgba(255,255,255,.1);
  margin: .25rem 0;
}

.sidebar-nav {
  list-style: none;
  padding: .5rem 0;
  margin: 0;
  flex: 1;
}

.nav-section { margin-top: .5rem; }
.nav-section-title {
  display: block;
  padding: .4rem 1.25rem .2rem;
  font-size: .65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: rgba(255,255,255,.4);
}

.sidebar-nav .nav-link {
  display: flex;
  align-items: center;
  gap: .6rem;
  padding: .55rem 1.25rem;
  color: var(--sidebar-text);
  text-decoration: none;
  border-radius: 0;
  font-size: .84rem;
  transition: var(--transition);
}

.sidebar-nav .nav-link:hover {
  background: var(--sidebar-hover-bg);
  color: #fff;
}

.sidebar-nav .nav-link.active {
  background: var(--sidebar-active-bg);
  color: #fff;
  border-right: 3px solid #64b5f6;
}

.sidebar-nav .nav-link i:first-child { font-size: 1rem; min-width: 1.25rem; }
.nav-arrow { font-size: .7rem; transition: transform .2s; }
.nav-link[aria-expanded="true"] .nav-arrow { transform: rotate(180deg); }

.nav-sub {
  list-style: none;
  padding: 0;
  margin: 0;
  background: rgba(0,0,0,.15);
}

.nav-sub a {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .4rem 1.25rem .4rem 2.5rem;
  color: var(--sidebar-text);
  text-decoration: none;
  font-size: .82rem;
  transition: var(--transition);
}

.nav-sub a:hover { color: #fff; background: rgba(255,255,255,.05); }

.sidebar-footer {
  padding: .75rem 1rem;
  border-top: 1px solid rgba(255,255,255,.1);
}

/* Sidebar Collapsed */
body.sidebar-collapsed .main-content { margin-left: 0; }
body.sidebar-collapsed .sidebar { transform: translateX(-100%); }

/* Overlay */
.sidebar-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.5);
  z-index: 1035;
  display: none;
}
.sidebar-overlay.show { display: block; }

/* ─── Top Navbar ─────────────────────────────────────────── */
.top-navbar {
  height: var(--navbar-height);
  background: var(--bs-body-bg);
  border-bottom: 1px solid var(--bs-border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1rem;
  position: sticky;
  top: 0;
  z-index: 1030;
  box-shadow: 0 1px 4px rgba(0,0,0,.06);
}

.navbar-left { display: flex; align-items: center; gap: .5rem; }
.navbar-right { display: flex; align-items: center; gap: .5rem; }
.sidebar-toggle { color: var(--bs-body-color); padding: .4rem; }

/* ─── Stat Cards ─────────────────────────────────────────── */
.stat-card {
  border-radius: var(--card-radius);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  border: 1px solid transparent;
  position: relative;
  overflow: hidden;
  transition: transform .15s, box-shadow .15s;
}

.stat-card:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(0,0,0,.12); }

.stat-card-primary  { background: linear-gradient(135deg, #1565c0, #1e88e5); color: #fff; border-color: #1565c0; }
.stat-card-success  { background: linear-gradient(135deg, #2e7d32, #43a047); color: #fff; border-color: #2e7d32; }
.stat-card-warning  { background: linear-gradient(135deg, #e65100, #fb8c00); color: #fff; border-color: #e65100; }
.stat-card-info     { background: linear-gradient(135deg, #0277bd, #039be5); color: #fff; border-color: #0277bd; }
.stat-card-danger   { background: linear-gradient(135deg, #b71c1c, #e53935); color: #fff; border-color: #b71c1c; }

.stat-card-icon {
  font-size: 2rem;
  opacity: .25;
  position: absolute;
  right: 1rem;
  top: .75rem;
}

.stat-card-value { font-size: 2rem; font-weight: 700; line-height: 1; }
.stat-card-label { font-size: .8rem; opacity: .85; margin-top: .2rem; }
.stat-card-link  {
  font-size: .75rem;
  color: rgba(255,255,255,.75);
  text-decoration: none;
  margin-top: .75rem;
  display: inline-flex;
  align-items: center;
  gap: .25rem;
}
.stat-card-link:hover { color: #fff; }

/* ─── Cards ──────────────────────────────────────────────── */
.card {
  border-radius: var(--card-radius);
  border: 1px solid var(--bs-border-color);
  box-shadow: 0 1px 4px rgba(0,0,0,.05);
}

.card-header {
  background: var(--bs-body-bg);
  border-bottom: 1px solid var(--bs-border-color);
  padding: .75rem 1rem;
  border-radius: var(--card-radius) var(--card-radius) 0 0 !important;
}

/* ─── Tables ─────────────────────────────────────────────── */
.table th { font-size: .78rem; font-weight: 600; white-space: nowrap; }
.table td { font-size: .83rem; vertical-align: middle; }
.table-responsive { overflow-x: auto; }

.cumulative-table th, .cumulative-table td {
  padding: .3rem .5rem;
  font-size: .75rem;
}

/* ─── Forms ──────────────────────────────────────────────── */
.form-control:focus, .form-select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 .2rem rgba(21,101,192,.15);
}

.marks-input {
  min-width: 65px;
  max-width: 90px;
  text-align: center;
}

.marks-input.is-invalid { border-color: var(--danger); animation: shake .3s; }

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

/* ─── Buttons ────────────────────────────────────────────── */
.btn-xs {
  padding: .15rem .45rem;
  font-size: .72rem;
  border-radius: 4px;
}

/* ─── Activity Dot ───────────────────────────────────────── */
.activity-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* ─── Loading Overlay ────────────────────────────────────── */
.loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.5);
  z-index: 9998;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ─── Footer ─────────────────────────────────────────────── */
.app-footer {
  text-align: center;
  padding: .75rem 1rem;
  font-size: .75rem;
  color: var(--bs-secondary-color);
  border-top: 1px solid var(--bs-border-color);
  background: var(--bs-body-bg);
}

/* ─── Badge fix ──────────────────────────────────────────── */
.badge { font-weight: 500; }

/* ─── Dark Mode Adjustments ─────────────────────────────── */
[data-bs-theme="dark"] {
  .card { box-shadow: 0 1px 4px rgba(0,0,0,.3); }
  .top-navbar { box-shadow: 0 1px 4px rgba(0,0,0,.2); }
}

/* ─── Responsive ─────────────────────────────────────────── */
@media (max-width: 991.98px) {
  .sidebar {
    transform: translateX(-100%);
  }
  .sidebar.show {
    transform: translateX(0);
  }
  .main-content {
    margin-left: 0 !important;
  }
  .content-area {
    padding: 1rem .75rem;
  }
}

@media (max-width: 575.98px) {
  .stat-card-value { font-size: 1.5rem; }
  .content-area { padding: .75rem .5rem; }
}