/* =====================================================
   AI ADAPTIVE EXAM SYSTEM — Main Stylesheet
   Dark / Light theme via data-theme attribute
===================================================== */

/* Google Font */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap');

/* ── Theme variables ── */
:root {
  --bg:        #0a0a0f;
  --bg2:       #111118;
  --bg3:       #18181f;
  --card:      #16161d;
  --border:    #222230;
  --border2:   #2a2a3a;
  --text:      #e8e8f0;
  --text2:     #a0a0b8;
  --text3:     #606078;
  --accent:    #2563eb;
  --accent-h:  #1d4ed8;
  --accent2:   #4f46e5;
  --blue-glow: rgba(37,99,235,0.15);
  --green:     #16a34a;
  --green-bg:  #052e16;
  --red:       #dc2626;
  --red-bg:    #2a0a0a;
  --yellow:    #ca8a04;
  --yellow-bg: #1c1400;
  --white:     #ffffff;
  --radius:    10px;
  --radius-sm: 7px;
  --shadow:    0 4px 24px rgba(0,0,0,0.5);
  --font:      'Inter', system-ui, sans-serif;
  --mono:      'JetBrains Mono', monospace;
  --transition: 0.18s ease;
}

[data-theme="light"] {
  --bg:        #f0f2f8;
  --bg2:       #ffffff;
  --bg3:       #f5f6fa;
  --card:      #ffffff;
  --border:    #dde1ee;
  --border2:   #c8cde0;
  --text:      #0f1020;
  --text2:     #4a4f6a;
  --text3:     #8888a0;
  --blue-glow: rgba(37,99,235,0.08);
  --green-bg:  #dcfce7;
  --red-bg:    #fee2e2;
  --yellow-bg: #fef9c3;
  --shadow:    0 4px 24px rgba(0,0,0,0.1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  font-size: 14px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background var(--transition), color var(--transition);
}

a { color: var(--accent); text-decoration: none; }
a:hover { opacity: 0.8; }

::-webkit-scrollbar { width: 5px; height: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 3px; }

/* ── Layout helpers ── */
.page-center {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px 16px;
}

.hidden { display: none !important; }

/* ── Cards ── */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
  transition: all var(--transition);
  white-space: nowrap;
  letter-spacing: 0.2px;
  text-decoration: none;
}
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none !important; }
.btn:not(:disabled):hover { transform: translateY(-1px); }

.btn-primary   { background: var(--accent);  color: #fff; border-color: var(--accent); }
.btn-primary:not(:disabled):hover { background: var(--accent-h); border-color: var(--accent-h); }
.btn-secondary { background: var(--accent2); color: #fff; border-color: var(--accent2); }
.btn-ghost     { background: transparent; color: var(--text); border-color: var(--border2); }
.btn-ghost:not(:disabled):hover { background: var(--bg3); }
.btn-danger    { background: var(--red); color: #fff; }
.btn-success   { background: var(--green); color: #fff; }
.btn-full      { width: 100%; }
.btn-sm        { padding: 7px 14px; font-size: 12px; }

/* ── Inputs ── */
.field { margin-bottom: 16px; }
.field label {
  display: block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--text2);
  margin-bottom: 6px;
}
.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 10px 13px;
  background: var(--bg3);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 14px;
  font-family: var(--font);
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.field input:focus,
.field select:focus,
.field textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--blue-glow);
}
.field .err { font-size: 11px; color: var(--red); margin-top: 4px; min-height: 15px; }
.field select option { background: var(--bg3); color: var(--text); }

/* ── Google button ── */
.google-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  padding: 10px 16px;
  background: var(--white);
  border: 1.5px solid #ddd;
  border-radius: var(--radius-sm);
  color: #333;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
  transition: box-shadow var(--transition);
  text-decoration: none;
}
.google-btn:hover { box-shadow: 0 2px 10px rgba(0,0,0,0.15); }
.google-btn img { width: 18px; height: 18px; }

/* ── Divider ── */
.divider {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 16px 0;
  color: var(--text3);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 1px;
}
.divider::before, .divider::after { content: ''; flex: 1; height: 1px; background: var(--border); }

/* ── Badges ── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 9px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.3px;
}
.badge-blue   { background: #1e3a6e; color: #93c5fd; }
.badge-green  { background: var(--green-bg); color: #4ade80; }
.badge-yellow { background: var(--yellow-bg); color: #fbbf24; }
.badge-red    { background: var(--red-bg); color: #f87171; }
.badge-purple { background: #1e1a40; color: #c4b5fd; }

[data-theme="light"] .badge-blue   { background: #dbeafe; color: #1d4ed8; }
[data-theme="light"] .badge-green  { background: #dcfce7; color: #15803d; }
[data-theme="light"] .badge-yellow { background: #fef9c3; color: #a16207; }
[data-theme="light"] .badge-red    { background: #fee2e2; color: #b91c1c; }
[data-theme="light"] .badge-purple { background: #ede9fe; color: #6d28d9; }

/* ── Toast ── */
.toast {
  position: fixed;
  top: 16px;
  right: 16px;
  padding: 11px 18px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  z-index: 99999;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-6px);
  transition: opacity 0.25s, transform 0.25s;
  max-width: 320px;
  box-shadow: var(--shadow);
  border: 1px solid transparent;
}
.toast.show   { opacity: 1; transform: translateY(0); }
.toast.success { background: var(--green-bg); color: #4ade80; border-color: #166534; }
.toast.error   { background: var(--red-bg);   color: #f87171; border-color: #7f1d1d; }
.toast.info    { background: #0c1a3a;          color: #93c5fd; border-color: #1e3a6e; }
.toast.warn    { background: var(--yellow-bg); color: #fbbf24; border-color: #713f12; }

[data-theme="light"] .toast.success { background: #dcfce7; color: #15803d; border-color: #86efac; }
[data-theme="light"] .toast.error   { background: #fee2e2; color: #b91c1c; border-color: #fca5a5; }
[data-theme="light"] .toast.info    { background: #dbeafe; color: #1d4ed8; border-color: #93c5fd; }

/* ── Spinner ── */
.spinner {
  width: 32px; height: 32px;
  border: 3px solid var(--border2);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.65s linear infinite;
  flex-shrink: 0;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Progress bar ── */
.prog-wrap { background: var(--border); border-radius: 10px; height: 5px; overflow: hidden; }
.prog-fill { height: 100%; background: var(--accent); border-radius: 10px; transition: width 0.4s ease; }

/* ── Theme toggle ── */
.theme-toggle {
  width: 36px; height: 36px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--bg3);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  transition: all var(--transition);
  flex-shrink: 0;
}
.theme-toggle:hover { border-color: var(--accent); }

/* ── Rank colors ── */
.rank-S { color: #fbbf24; }
.rank-A { color: #a78bfa; }
.rank-B { color: #60a5fa; }
.rank-C { color: #34d399; }
.rank-D { color: #fb923c; }
.rank-F { color: #6b7280; }

/* ── Step bar ── */
.step-bar { display: flex; align-items: center; margin-bottom: 32px; }
.step-item { display: flex; align-items: center; gap: 8px; }
.step-circle {
  width: 30px; height: 30px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 700; flex-shrink: 0;
  border: 2px solid var(--border2);
  color: var(--text3);
  background: var(--card);
  transition: all var(--transition);
}
.step-item.done   .step-circle { background: var(--green); border-color: var(--green); color: #fff; }
.step-item.active .step-circle { background: var(--accent); border-color: var(--accent); color: #fff; }
.step-label { font-size: 12px; font-weight: 600; color: var(--text3); }
.step-item.active .step-label { color: var(--text); }
.step-line { flex: 1; height: 1px; background: var(--border); margin: 0 6px; }
.step-line.done { background: var(--green); }

/* ── Table ── */
.tbl { width: 100%; border-collapse: collapse; }
.tbl th { font-size: 10px; font-weight: 700; letter-spacing: 1.2px; text-transform: uppercase; color: var(--text3); padding: 10px 14px; text-align: left; border-bottom: 1px solid var(--border); }
.tbl td { padding: 11px 14px; font-size: 13px; border-bottom: 1px solid var(--border); }
.tbl tr:last-child td { border-bottom: none; }
.tbl tr:hover td { background: var(--bg3); }

/* ── Pill select ── */
.pill-row { display: flex; gap: 8px; flex-wrap: wrap; }
.pill {
  padding: 8px 16px; border-radius: 20px;
  border: 1.5px solid var(--border2);
  background: var(--bg3);
  color: var(--text2);
  cursor: pointer; font-size: 13px; font-weight: 600;
  transition: all var(--transition);
  user-select: none;
}
.pill.active { border-color: var(--accent); background: var(--blue-glow); color: var(--accent); }
.pill:hover:not(.active) { border-color: var(--border2); color: var(--text); }

/* ── Dropdown ── */
.dropdown-wrap { position: relative; }
.dropdown-list {
  position: absolute; top: calc(100% + 4px);
  left: 0; right: 0;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  max-height: 210px; overflow-y: auto;
  z-index: 200; display: none;
  box-shadow: var(--shadow);
}
.dropdown-list.open { display: block; }
.dropdown-item { padding: 9px 13px; font-size: 13px; cursor: pointer; color: var(--text); transition: background var(--transition); }
.dropdown-item:hover { background: var(--bg3); }
.selected-tag { margin-top: 7px; padding: 6px 12px; background: var(--blue-glow); border: 1px solid var(--accent); border-radius: var(--radius-sm); font-size: 12px; color: var(--accent); font-weight: 600; display: none; }

/* ── Class grid ── */
.class-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 7px; margin-top: 12px; }
.class-chip {
  padding: 9px 6px; border-radius: var(--radius-sm); text-align: center;
  border: 1.5px solid var(--border); background: var(--bg3);
  color: var(--text2); cursor: pointer; font-size: 13px; font-weight: 600;
  transition: all var(--transition);
}
.class-chip.active { border-color: var(--accent2); background: rgba(79,70,229,0.15); color: #a78bfa; }

/* ── Photo zone ── */
.photo-zone {
  border: 2px dashed var(--border2); border-radius: var(--radius);
  padding: 28px; text-align: center; cursor: pointer;
  position: relative; transition: border-color var(--transition);
}
.photo-zone:hover { border-color: var(--accent); }
.photo-zone input[type="file"] { position: absolute; inset: 0; opacity: 0; cursor: pointer; width: 100%; height: 100%; }
.photo-preview { width: 100px; height: 100px; border-radius: 50%; object-fit: cover; margin: 0 auto 10px; display: none; border: 3px solid var(--accent); }

/* ── Home sidebar layout ── */
.app-layout { display: grid; grid-template-columns: 240px 1fr; min-height: 100vh; }
.sidebar {
  background: var(--card);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  padding: 16px;
  position: sticky; top: 0; height: 100vh; overflow-y: auto;
}
.sidebar-logo { display: flex; align-items: center; gap: 10px; padding: 8px 10px; margin-bottom: 20px; }
.sidebar-logo-icon { font-size: 22px; }
.sidebar-logo-text { font-size: 14px; font-weight: 800; color: var(--text); }
.sidebar-logo-text span { color: var(--accent); }
.nav-section-label { font-size: 10px; font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase; color: var(--text3); padding: 12px 10px 4px; }
.nav-btn {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 12px; border-radius: var(--radius-sm);
  font-size: 13px; font-weight: 500; color: var(--text2);
  cursor: pointer; border: none; background: transparent;
  font-family: var(--font); transition: all var(--transition);
  width: 100%; text-align: left;
}
.nav-btn:hover  { background: var(--bg3); color: var(--text); }
.nav-btn.active { background: var(--blue-glow); color: var(--accent); border-left: 3px solid var(--accent); }
.nav-icon { font-size: 15px; width: 20px; text-align: center; flex-shrink: 0; }
.sidebar-bottom { margin-top: auto; padding-top: 12px; border-top: 1px solid var(--border); display: flex; flex-direction: column; gap: 6px; }
.user-chip { display: flex; align-items: center; gap: 10px; padding: 10px; border-radius: var(--radius-sm); background: var(--bg3); }
.user-av { width: 32px; height: 32px; border-radius: 50%; background: linear-gradient(135deg, var(--accent), var(--accent2)); display: flex; align-items: center; justify-content: center; font-size: 13px; font-weight: 800; color: #fff; flex-shrink: 0; }
.user-name { font-size: 12px; font-weight: 600; color: var(--text); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.user-email { font-size: 11px; color: var(--text3); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.main-area { padding: 28px; overflow-y: auto; background: var(--bg); }
.page-view { display: none; }
.page-view.active { display: block; }
.page-title { font-size: 1.4rem; font-weight: 800; color: var(--text); margin-bottom: 4px; }
.page-subtitle { font-size: 13px; color: var(--text2); margin-bottom: 24px; }

/* ── Stat cards ── */
.stat-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 12px; margin-bottom: 24px; }
.stat-card { padding: 18px; border-radius: var(--radius); }
.stat-label { font-size: 10px; font-weight: 700; letter-spacing: 1.2px; text-transform: uppercase; color: var(--text3); margin-bottom: 6px; }
.stat-val   { font-size: 1.8rem; font-weight: 800; color: var(--text); line-height: 1; }
.stat-sub   { font-size: 11px; color: var(--text3); margin-top: 4px; }

/* ── Subject cards ── */
.subject-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 14px; }
.subject-card {
  padding: 20px; border-radius: var(--radius);
  background: var(--card); border: 1px solid var(--border);
  cursor: pointer; transition: all var(--transition);
}
.subject-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: 0 6px 20px var(--blue-glow); }
.subj-icon { font-size: 28px; margin-bottom: 10px; }
.subj-name { font-size: 14px; font-weight: 700; color: var(--text); margin-bottom: 8px; }
.subj-meta { font-size: 11px; color: var(--text3); display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 10px; }
.diff-row { display: flex; gap: 5px; flex-wrap: wrap; }
.diff-chip {
  padding: 3px 9px; border-radius: 10px; font-size: 11px; font-weight: 600;
  cursor: pointer; border: 1px solid transparent; transition: all var(--transition);
}
.diff-easy { background: var(--green-bg); color: #4ade80; border-color: #166534; }
.diff-mod  { background: var(--yellow-bg); color: #fbbf24; border-color: #713f12; }
.diff-hard { background: var(--red-bg);   color: #f87171; border-color: #7f1d1d; }
.diff-chip:hover { filter: brightness(1.2); }

/* ── Responsive ── */
@media (max-width: 768px) {
  .app-layout { grid-template-columns: 1fr; }
  .sidebar { height: auto; position: static; flex-direction: row; overflow-x: auto; padding: 8px 10px; flex-wrap: wrap; }
  .nav-section-label, .sidebar-logo-text, .user-name, .user-email, .sidebar-bottom { display: none; }
  .nav-btn { padding: 8px; }
  .main-area { padding: 16px; }
  .class-grid { grid-template-columns: repeat(3, 1fr); }
}