/* ── CSS Variables ── */
:root {
  --bg: #0A0A14;
  --bg2: #12121F;
  --card: #1A1A2E;
  --card-hover: #222238;
  --border: rgba(255,255,255,0.08);
  --text: #FFFFFF;
  --text2: rgba(255,255,255,0.6);
  --text3: rgba(255,255,255,0.35);
  --primary: #6C63FF;
  --primary-light: rgba(108,99,255,0.15);
  --accent: #C4B5FD;
  --pink: #F472B6;
  --green: #10B981;
  --amber: #F59E0B;
  --red: #EF4444;
  --shadow: 0 4px 20px rgba(0,0,0,0.4);
  --shadow-glow: 0 0 20px rgba(108,99,255,0.3);
  --radius: 14px;
  --radius-sm: 8px;
  --header-h: 60px;
  --nav-h: 60px;
}

[data-theme="light"] {
  --bg: #F0F2FF;
  --bg2: #E8EAFF;
  --card: #FFFFFF;
  --card-hover: #F5F5FF;
  --border: rgba(108,99,255,0.12);
  --text: #1A1A2E;
  --text2: rgba(26,26,46,0.65);
  --text3: rgba(26,26,46,0.4);
  --shadow: 0 4px 20px rgba(108,99,255,0.1);
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Noto Sans Bengali', 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  padding-top: var(--header-h);
  padding-bottom: var(--nav-h);
  transition: background 0.3s, color 0.3s;
}
a { text-decoration: none; color: inherit; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select { font-family: inherit; }

/* ── ATLAS Gradient Text ── */
@keyframes gradShift {
  0%   { background-position: 0% 50%; }
  50%  { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}
.atlas-brand {
  background: linear-gradient(135deg, #818CF8, #C4B5FD, #F472B6, #818CF8);
  background-size: 300% 300%;
  animation: gradShift 3s linear infinite;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 900;
  letter-spacing: 3px;
}

/* ── Header Logo ── */
.logo-link {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 9px;
  text-decoration: none;
  min-width: 0;
}
.logo-icon {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
}
.logo-text-block {
  display: flex;
  flex-direction: column;
  line-height: 1;
}
.logo-name {
  font-size: 19px;
  font-weight: 900;
  color: var(--text);
  letter-spacing: 1.5px;
  font-family: 'Inter', sans-serif;
}
.logo-name .logo-a { color: #4ADE80; }
.logo-sub {
  font-size: 8.5px;
  color: var(--text3);
  margin-top: 2px;
  letter-spacing: 0.3px;
  font-family: 'Noto Sans Bengali', sans-serif;
  white-space: nowrap;
}

/* ── Header ── */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 14px;
  gap: 10px;
  z-index: 100;
  backdrop-filter: blur(12px);
}
.header-brand {
  flex: 1;
  font-size: 20px;
}
.header-actions {
  display: flex;
  align-items: center;
  gap: 4px;
}
.icon-btn {
  width: 38px; height: 38px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  background: var(--card);
  border: 1px solid var(--border);
  font-size: 16px;
  cursor: pointer;
  transition: all 0.2s;
  color: var(--text);
}
.icon-btn:hover { background: var(--card-hover); border-color: var(--primary); }
.avatar-btn {
  width: 38px; height: 38px;
  border-radius: 50%;
  background: var(--primary-light);
  border: 2px solid var(--primary);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
  font-size: 15px;
  color: var(--primary);
  cursor: pointer;
}
.menu-btn { font-size: 20px; color: var(--text2); }

/* ── Sidebar ── */
.sidebar-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: 200;
  opacity: 0; pointer-events: none;
  transition: opacity 0.3s;
}
.sidebar-overlay.open { opacity: 1; pointer-events: all; }
.sidebar {
  position: fixed;
  top: 0; left: -280px; bottom: 0;
  width: 260px;
  background: var(--bg2);
  border-right: 1px solid var(--border);
  z-index: 201;
  transition: left 0.3s cubic-bezier(.4,0,.2,1);
  display: flex; flex-direction: column;
  overflow-y: auto;
}
.sidebar.open { left: 0; }
.sidebar-header {
  padding: 20px 16px 16px;
  border-bottom: 1px solid var(--border);
}
.sidebar-user {
  display: flex; align-items: center; gap: 12px;
  padding: 16px;
  border-bottom: 1px solid var(--border);
}
.sidebar-avatar {
  width: 44px; height: 44px;
  border-radius: 50%;
  background: var(--primary-light);
  border: 2px solid var(--primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 18px; font-weight: 700; color: var(--primary);
}
.sidebar-name { font-weight: 700; font-size: 14px; }
.sidebar-badge {
  font-size: 10px; padding: 2px 8px;
  border-radius: 20px;
  display: inline-block; margin-top: 2px;
}
.badge-free { background: rgba(99,179,237,0.15); color: #63B3ED; }
.badge-premium { background: rgba(245,158,11,0.15); color: var(--amber); }
.sidebar-nav { padding: 8px 0; flex: 1; }
.sidebar-link {
  display: flex; align-items: center; gap: 12px;
  padding: 13px 16px;
  color: var(--text2);
  font-size: 14px;
  transition: all 0.2s;
  cursor: pointer;
}
.sidebar-link:hover, .sidebar-link.active {
  background: var(--primary-light);
  color: var(--primary);
}
.sidebar-link span { font-size: 18px; }
.sidebar-divider { height: 1px; background: var(--border); margin: 6px 0; }
.sidebar-admin {
  margin: 8px 16px;
  padding: 12px;
  border-radius: var(--radius-sm);
  background: rgba(245,158,11,0.08);
  border: 1px solid rgba(245,158,11,0.25);
  cursor: pointer;
  display: flex; align-items: center; gap: 10px;
  font-size: 14px; font-weight: 700;
  color: var(--amber);
}
.sidebar-logout {
  margin: 8px 16px 20px;
  padding: 12px;
  border-radius: var(--radius-sm);
  background: rgba(239,68,68,0.08);
  border: 1px solid rgba(239,68,68,0.2);
  cursor: pointer;
  display: flex; align-items: center; gap: 10px;
  font-size: 14px; font-weight: 600;
  color: var(--red);
}

/* ── Announcement Slideshow ── */
.slideshow-wrap {
  margin: 14px 14px 0;
  border-radius: var(--radius);
  overflow: hidden;
  position: relative;
}
.slide {
  display: none;
  padding: 16px;
  border-radius: var(--radius);
  position: relative;
  min-height: 80px;
  background: linear-gradient(135deg, var(--card), var(--bg2));
  border: 1px solid var(--border);
  animation: fadeSlide 0.4s ease;
}
.slide.active { display: block; }
@keyframes fadeSlide {
  from { opacity:0; transform:translateX(30px); }
  to   { opacity:1; transform:translateX(0); }
}
.slide-title { font-weight: 700; font-size: 14px; margin-bottom: 4px; }
.slide-text { font-size: 12px; color: var(--text2); line-height: 1.5; }
.slide-dots {
  display: flex; gap: 5px; justify-content: center;
  margin-top: 10px;
}
.slide-dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--border); transition: all 0.3s;
}
.slide-dot.active { background: var(--primary); width: 18px; border-radius: 3px; }

/* ── Greeting ── */
.greeting {
  padding: 16px 14px 0;
}
.greeting-name { font-size: 18px; font-weight: 700; }
.greeting-badge {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 11px; font-weight: 700;
  margin-top: 6px;
}
.greeting-upgrade {
  font-size: 11px; font-weight: 700;
  color: var(--primary);
  cursor: pointer; margin-left: 8px;
}

/* ── Section Label ── */
.section-label {
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 14px 8px;
}
.section-title {
  font-size: 11px; font-weight: 700;
  letter-spacing: 1px;
  color: var(--text3);
  text-transform: uppercase;
}

/* ── Subject Grid ── */
.subject-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  padding: 0 14px;
}
.subject-card {
  border-radius: var(--radius);
  padding: 16px 12px;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  position: relative;
  overflow: hidden;
  min-height: 100px;
  display: flex; flex-direction: column;
}
.subject-card:hover { transform: translateY(-2px); }
.subject-icon { font-size: 26px; margin-bottom: auto; }
.subject-name {
  font-size: 13px; font-weight: 700;
  color: #fff;
  margin-top: 10px;
  line-height: 1.3;
}
.subject-meta {
  font-size: 10px; color: rgba(255,255,255,0.6);
  margin-top: 4px;
  display: flex; align-items: center; gap: 4px;
}

/* ── Quick Action Grid ── */
.quick-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  padding: 0 14px;
}
.quick-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 12px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  display: flex; flex-direction: column;
  align-items: center; gap: 8px;
}
.quick-card:hover {
  border-color: var(--primary);
  background: var(--card-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}
.quick-card.full-width { grid-column: 1/-1; }
.quick-icon { font-size: 30px; }
.quick-label {
  font-size: 13px; font-weight: 700;
  color: var(--text);
}
.quick-sub { font-size: 10px; color: var(--text3); }
.quick-card.admin-card {
  border-color: rgba(245,158,11,0.3);
  background: rgba(245,158,11,0.06);
}
.quick-card.admin-card .quick-label { color: var(--amber); }

/* ── Owner Flip Card ── */
.owner-section { padding: 0 14px; }
.flip-card {
  width: 100%;
  height: 200px;
  perspective: 1000px;
  cursor: pointer;
}
.flip-card-inner {
  position: relative; width: 100%; height: 100%;
  transition: transform 0.7s cubic-bezier(.4,.2,.2,1);
  transform-style: preserve-3d;
}
.flip-card.flipped .flip-card-inner { transform: rotateY(180deg); }
.flip-front, .flip-back {
  position: absolute; width: 100%; height: 100%;
  backface-visibility: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  overflow: hidden;
  display: flex; align-items: center; justify-content: center;
}
.flip-front {
  background: var(--card);
  flex-direction: column; gap: 10px;
}
.flip-back {
  background: linear-gradient(135deg, var(--card), var(--bg2));
  transform: rotateY(180deg);
  padding: 20px;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
}
.owner-photo {
  width: 80px; height: 80px; border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--primary);
  position: relative; z-index: 1;
}
.owner-glow {
  position: absolute;
  width: 90px; height: 90px; border-radius: 50%;
  border: 2px solid var(--primary);
  animation: glow-spin 3s linear infinite;
  border-top-color: var(--pink);
  border-right-color: transparent;
}
@keyframes glow-spin {
  to { transform: rotate(360deg); }
}

/* ── Floating Buttons ── */
.float-btns {
  position: fixed;
  bottom: calc(var(--nav-h) + 16px);
  right: 14px;
  display: flex; flex-direction: column;
  gap: 10px;
  z-index: 90;
}
.float-btn {
  width: 50px; height: 50px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 22px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.3);
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none;
}
.float-btn:hover { transform: scale(1.1); box-shadow: 0 6px 24px rgba(0,0,0,0.4); }
.float-wa { background: #25D366; }
.float-tg { background: #229ED9; }

/* ── Bottom Nav ── */
.bottom-nav {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  height: var(--nav-h);
  background: var(--bg2);
  border-top: 1px solid var(--border);
  display: flex;
  z-index: 100;
}
.nav-item {
  flex: 1;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 3px;
  cursor: pointer;
  transition: all 0.2s;
  color: var(--text3);
  font-size: 10px;
  text-decoration: none;
}
.nav-item.active { color: var(--primary); }
.nav-icon { font-size: 20px; }

/* ── Loading ── */
.loader {
  display: flex; align-items: center; justify-content: center;
  min-height: 200px;
  flex-direction: column; gap: 12px;
}
.spinner {
  width: 36px; height: 36px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Empty State ── */
.empty {
  text-align: center; padding: 40px 20px;
  color: var(--text3);
}
.empty-icon { font-size: 48px; margin-bottom: 12px; }
.empty-title { font-size: 15px; font-weight: 700; color: var(--text2); margin-bottom: 6px; }
.empty-text { font-size: 12px; line-height: 1.6; }

/* ── Buttons ── */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-size: 14px; font-weight: 700;
  cursor: pointer; border: none;
  transition: all 0.2s;
  font-family: inherit;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: #5A52E0; box-shadow: var(--shadow-glow); }
.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 1.5px solid var(--primary);
}
.btn-outline:hover { background: var(--primary-light); }
.btn-full { width: 100%; }

/* ── Login CTA ── */
.login-cta {
  margin: 20px 14px;
  padding: 24px;
  border-radius: var(--radius);
  background: var(--card);
  border: 1px solid var(--border);
  text-align: center;
}
.login-cta-icon { font-size: 40px; margin-bottom: 12px; }
.login-cta-title { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.login-cta-text { font-size: 12px; color: var(--text2); margin-bottom: 16px; line-height: 1.5; }

/* ── Toast ── */
.toast {
  position: fixed; bottom: calc(var(--nav-h) + 80px); left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--card);
  border: 1px solid var(--border);
  padding: 10px 20px;
  border-radius: 30px;
  font-size: 13px; font-weight: 600;
  opacity: 0; transition: all 0.3s;
  z-index: 300; white-space: nowrap;
  box-shadow: var(--shadow);
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ── Utility ── */
.mt-8  { margin-top:  8px; }
.mt-12 { margin-top: 12px; }
.mt-16 { margin-top: 16px; }
.mb-16 { margin-bottom: 16px; }
.px-14 { padding-left: 14px; padding-right: 14px; }
.text-center { text-align: center; }
.text-sm { font-size: 12px; color: var(--text2); }

/* ── Responsive ── */
@media (min-width: 480px) {
  .subject-grid { grid-template-columns: repeat(3, 1fr); }
  .quick-grid   { grid-template-columns: repeat(3, 1fr); }
}
@media (min-width: 768px) {
  body { max-width: 480px; margin: 0 auto; }
  .header, .bottom-nav, .sidebar, .float-btns {
    max-width: 480px;
    left: 50%; transform: translateX(-50%);
    right: auto; width: 480px;
  }
  .sidebar { transform: none; left: calc(50% - 240px); }
  .sidebar.open { left: calc(50% - 240px); }
}