/*
  main.css
  Modern UI refresh (vanilla CSS)

  What changed (high level):
  - Introduced a simple design system using CSS variables (colors, spacing, radius, shadows)
  - Added a consistent layout container and reusable UI components (buttons, cards, badges)
  - Improved typography (uses Inter which you already import) and spacing
  - Added responsive behavior for header/search, sidebar, grids, and media
  - Added subtle hover + focus effects and smooth transitions
*/

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@100..900&family=Nunito:wght@200..1000&display=swap');

/* =========================
   Design tokens
   ========================= */
:root{
  --color-bg: #f6f7fb;
  --color-surface: #ffffff;
  --color-text: #0f172a;
  --color-muted: #475569;
  --color-border: rgba(15, 23, 42, 0.12);

  --color-primary: #3b82f6;
  --color-primary-600: #2563eb;
  --color-accent: #0f172a;

  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 18px;

  --shadow-sm: 0 8px 24px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 16px 46px rgba(15, 23, 42, 0.10);

  --container: 1100px;

  --space-1: 6px;
  --space-2: 10px;
  --space-3: 14px;
  --space-4: 18px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 44px;

  --transition: 180ms ease;
}

/* Dark mode: your JS toggles body.dark */
body.dark{
  --color-bg: #070d18;
  --color-surface: #0b1220;
  --color-text: #e5e7eb;
  --color-muted: #cbd5e1;
  --color-border: rgba(226, 232, 240, 0.16);

  --shadow-sm: 0 12px 30px rgba(0, 0, 0, 0.30);
  --shadow-md: 0 22px 60px rgba(0, 0, 0, 0.42);
}

/* =========================
   Base styles
   ========================= */
*{ box-sizing: border-box; }

html{
  font-size: 62.5%;
  overflow-x: hidden;
  scroll-behavior: smooth;
}

body{
  margin: 0;
  font-family: 'Inter', 'Nunito', system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  color: var(--color-text);
  background:
    radial-gradient(1100px 650px at 15% -25%, rgba(59, 130, 246, 0.18), transparent 60%),
    radial-gradient(900px 500px at 110% 10%, rgba(15, 23, 42, 0.12), transparent 55%),
    var(--color-bg);
  line-height: 1.6;
  padding-left: 0;
}

body.dark{
  background:
    radial-gradient(900px 520px at 18% -20%, rgba(59, 130, 246, 0.16), transparent 62%),
    radial-gradient(900px 520px at 120% 0%, rgba(148, 163, 184, 0.10), transparent 56%),
    var(--color-bg);
}

body.active{
  overflow: hidden;
}

img{ max-width: 100%; display: block; }

a{ color: inherit; text-decoration: none; }

/* selection + scrollbar */
*::selection{ background: rgba(59, 130, 246, 0.22); }

*::-webkit-scrollbar{ width: 10px; height: 10px; }
*::-webkit-scrollbar-thumb{ background: rgba(100, 116, 139, 0.55); border-radius: 999px; }
*::-webkit-scrollbar-track{ background: transparent; }

/* =========================
   Layout helpers
   ========================= */
section{
  padding: var(--space-6) var(--space-5);
}

.container{
  max-width: var(--container);
  margin: 0 auto;
}

.section-title{
  font-size: 2.6rem;
  letter-spacing: -0.02em;
  margin: 0 0 var(--space-4);
}

.lead{
  font-size: 1.7rem;
  color: var(--color-muted);
  margin: 0;
}

/* =========================
   Reusable components
   ========================= */
.btn,
.option-btn,
.delete-btn,
.inline-btn,
.inline-option-btn,
.inline-delet-btn{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;

  border-radius: 999px;
  padding: 12px 18px;
  font-size: 1.6rem;
  font-weight: 700;

  cursor: pointer;
  border: 1px solid transparent;
  transition: transform var(--transition), box-shadow var(--transition), background-color var(--transition), color var(--transition);
}

.btn,
.inline-btn{
  background: var(--color-primary);
  color: #fff;
}

.btn:hover,
.inline-btn:hover{
  background: var(--color-primary-600);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.option-btn,
.inline-option-btn{
  background: var(--color-accent);
  color: #fff;
}

.option-btn:hover,
.inline-option-btn:hover{
  background: #111c35;
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.delete-btn,
.inline-delet-btn{
  background: #ef4444;
  color: #fff;
}

.delete-btn:hover,
.inline-delet-btn:hover{
  background: #dc2626;
  transform: translateY(-1px);
}

.card{
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.card:hover{
  transform: translateY(-2px);
  transition: transform var(--transition);
}

.badge{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 1.3rem;
  padding: 7px 12px;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  color: var(--color-muted);
  background: rgba(255, 255, 255, 0.6);
}

body.dark .badge{
  background: rgba(11, 18, 32, 0.55);
}

/* =========================
   Header
   ========================= */
.header{
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid var(--color-border);
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: blur(12px);
}

body.dark .header{
  background: rgba(11, 18, 32, 0.72);
}

body.dark .header{
  box-shadow: 0 10px 35px rgba(0, 0, 0, 0.25);
}

.header .flex{
  max-width: var(--container);
  margin: 0 auto;
  padding: 16px var(--space-5);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  position: relative;
}

.header .flex .logo{
  font-size: 2.2rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.header .flex .search-form{
  width: min(520px, 100%);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;

  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: rgba(255, 255, 255, 0.7);
  box-shadow: var(--shadow-sm);
}

body.dark .header .flex .search-form{
  background: rgba(11, 18, 32, 0.65);
}

.header .flex .search-form input{
  width: 100%;
  font-size: 1.5rem;
  background: transparent;
  color: var(--color-text);
  border: 0;
  outline: none;
}

.header .flex .search-form button{
  font-size: 1.8rem;
  background: transparent;
  color: var(--color-muted);
  cursor: pointer;
}

.header .flex .search-form button:hover{ color: var(--color-primary); }

.header .flex .icons{
  display: flex;
  align-items: center;
  gap: 12px;
}

.header .flex .icons div{
  height: 44px;
  width: 44px;
  border-radius: 14px;
  display: grid;
  place-items: center;

  background: rgba(100, 116, 139, 0.10);
  color: var(--color-text);
  cursor: pointer;
  transition: transform var(--transition), background-color var(--transition);
}

.header .flex .icons div:hover{
  transform: translateY(-1px);
  background: rgba(59, 130, 246, 0.16);
}

#search-btn{ display: none; }

/* Profile dropdown */
.header .flex .profile{
  position: absolute;
  top: calc(100% + 12px);
  right: var(--space-5);
  width: 320px;
  padding: var(--space-5);

  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  box-shadow: var(--shadow-md);

  transform: scale(0);
  transform-origin: top right;
}

.header .flex .profile.active{
  transform: scale(1);
  transition: transform var(--transition);
}

.header .flex .profile img{
  width: 92px;
  height: 92px;
  border-radius: 999px;
  object-fit: cover;
  margin: 0 auto var(--space-3);
}

.header .flex .profile span{
  display: block;
  font-size: 1.4rem;
  color: var(--color-muted);
  text-align: center;
  margin-bottom: var(--space-4);
}

.header .flex .profile .options{
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

/* =========================
   Sidebar
   ========================= */
.side-bar{
  position: fixed;
  inset: 0 auto 0 0;
  width: 30rem;
  height: 100vh;

  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  z-index: 1200;

  transform: translateX(-100%);
  transition: transform 260ms ease;
}

body.dark .side-bar{
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.02), transparent 55%), var(--color-surface);
}

/* JS toggles .active (open/close). Default state is open on desktop. */
.side-bar.active{
  transform: translateX(0);
}

.side-bar .close-side-bar{
  display: block;
  padding: var(--space-5);
  text-align: right;
}

.side-bar .close-side-bar i{
  height: 44px;
  width: 44px;
  border-radius: 14px;
  display: inline-grid;
  place-items: center;
  background: rgba(100, 116, 139, 0.18);
  cursor: pointer;
}

.side-bar h1{
  font-size: 1.8rem;
  margin: var(--space-6) var(--space-5) var(--space-3);
  line-height: 1.3;
}

.topbar{
  margin: 0 var(--space-5) var(--space-4);
  padding: 10px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: rgba(100, 116, 139, 0.08);
  display: flex;
  justify-content: flex-end;
  gap: 10px;
}

.side-bar .navbar{
  padding: 0 var(--space-3) var(--space-6);
}

.side-bar .navbar a{
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  margin: 8px 10px;
  border-radius: var(--radius-md);
  font-size: 1.6rem;

  color: var(--color-text);
  transition: background-color var(--transition), transform var(--transition);
}

.side-bar .navbar a:focus-visible{
  outline: 3px solid rgba(59, 130, 246, 0.35);
  outline-offset: 2px;
}

.side-bar .navbar a span{ color: var(--color-muted); }

.side-bar .navbar a:hover{
  background: rgba(59, 130, 246, 0.12);
  transform: translateX(2px);
}

.side-bar .navbar a i{ color: var(--color-primary); }

/* =========================
   Home sections
   ========================= */
.hero{
  padding-top: var(--space-7);
}

.hero .container{
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: var(--space-6);
  align-items: center;
}

.hero h1{
  font-size: 4.2rem;
  line-height: 1.08;
  letter-spacing: -0.03em;
  margin: 0 0 var(--space-4);
}

.hero p{
  font-size: 1.7rem;
  color: var(--color-muted);
  margin: 0 0 var(--space-5);
}

.hero .actions{
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero .hero-card{
  padding: var(--space-6);
}

.hero .hero-card .stats{
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: var(--space-4);
}

.hero .hero-card .stat{
  padding: 12px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: rgba(100, 116, 139, 0.06);
}

.hero .hero-card .stat strong{
  display: block;
  font-size: 2.2rem;
}

.hero .hero-card .stat span{
  font-size: 1.3rem;
  color: var(--color-muted);
}

/* Quick select + courses grids */
.quick-select .box-container,
.courses .box-container,
.reviews .box-container,
.teachers .box-container{
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(26rem, 1fr));
  gap: var(--space-5);
}

.quick-select .box,
.courses .box,
.reviews .box,
.teachers .box,
.about .box-container .box{
  padding: var(--space-5);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

.quick-select .title,
.courses .title{
  font-size: 1.9rem;
  margin: 0;
}

.quick-select p,
.courses p,
.reviews p,
.teachers p{
  font-size: 1.5rem;
  color: var(--color-muted);
}

.quick-select .flex{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: var(--space-4);
}

.quick-select .flex a{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: rgba(100, 116, 139, 0.06);
  transition: transform var(--transition), background-color var(--transition);
  font-size: 1.4rem;
}

.quick-select .flex a:hover{
  transform: translateY(-1px);
  background: rgba(59, 130, 246, 0.14);
}

.courses .teachers{
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: var(--space-4);
}

.courses .teachers img{
  width: 46px;
  height: 46px;
  border-radius: 999px;
  object-fit: cover;
}

.courses .teachers h3{
  font-size: 1.6rem;
  margin: 0;
}

.courses .teachers span{
  font-size: 1.3rem;
  color: var(--color-muted);
}

.courses .thumb{
  border-radius: var(--radius-md);
  height: 190px;
  object-fit: cover;
  margin-bottom: var(--space-3);
}

.more-btn{
  margin-top: var(--space-5);
  text-align: center;
}

/* Video / audio */
.video{
  padding: var(--space-6) var(--space-5);
}

.video video{
  width: min(100%, var(--container));
  display: block;
  margin: 0 auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  background: #000;
}

.audio{
  padding: 0 var(--space-5) var(--space-6);
}

.audio audio{
  width: min(100%, var(--container));
  display: block;
  margin: 0 auto;
}

/* Slideshow */
.slideshow{
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-6) var(--space-5);
}

.slide{
  display: none;
  width: min(100%, var(--container));
  max-height: 520px;
  object-fit: cover;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.slide.active{ display: block; }

/* Footer */
.footer{
  border-top: 1px solid var(--color-border);
  padding: var(--space-6) var(--space-5);
  background: rgba(100, 116, 139, 0.06);
}

.footer-content{
  max-width: var(--container);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-6);
}

.footer-section h3{
  margin: 0 0 var(--space-3);
  font-size: 1.8rem;
}

.footer-section p{
  margin: 0 0 var(--space-3);
  font-size: 1.5rem;
  color: var(--color-muted);
}

.social-media{
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  gap: 10px;
}

.social-media a{
  height: 42px;
  width: 42px;
  display: grid;
  place-items: center;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: rgba(255, 255, 255, 0.7);
  transition: transform var(--transition), background-color var(--transition);
}

.social-media a:hover{
  transform: translateY(-1px);
  background: rgba(59, 130, 246, 0.14);
}

.footer-bottom{
  max-width: var(--container);
  margin: var(--space-5) auto 0;
  text-align: center;
  color: var(--color-muted);
  font-size: 1.4rem;
}

/* =========================
   Responsive
   ========================= */
@media (max-width: 1200px){
  body{ padding-left: 0; }
}

@media (max-width: 991px){
  .header .flex{ flex-wrap: wrap; }

  .header .flex .search-form{ width: 100%; }

  .hero .container{ grid-template-columns: 1fr; }

  .footer-content{ grid-template-columns: 1fr; }
}

@media (max-width: 768px){
  #search-btn{ display: inline-grid; }

  .header .flex .search-form{
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    width: auto;
    margin: 0;
    border-radius: 0;
    border-left: 0;
    border-right: 0;

    transform: translateY(-10px);
    opacity: 0;
    pointer-events: none;
  }

  .header .flex .search-form.active{
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
    transition: opacity var(--transition), transform var(--transition);
  }
}

@media (prefers-reduced-motion: reduce){
  *{ transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}