/* ============================================
   PythonHindi.in — Main Stylesheet
   Google AdSense + SEO Ready
   ============================================ */

:root {
  --bg: #0d0f1a;
  --surface: #151825;
  --surface2: #1e2236;
  --border: #2a2f4a;
  --accent: #f7c948;
  --accent2: #4fc3f7;
  --accent3: #a78bfa;
  --green: #4ade80;
  --red: #f87171;
  --orange: #fb923c;
  --text: #e8eaf6;
  --text-dim: #8892b0;
  --code-bg: #0a0c15;
  --header-h: 64px;
  --max-w: 1100px;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Plus Jakarta Sans', sans-serif;
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { text-decoration: none; color: inherit; }

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== PROGRESS BAR ===== */
.top-progress {
  position: fixed; top: 0; left: 0; right: 0;
  height: 3px; background: var(--border); z-index: 9999;
}
.top-progress-fill {
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  width: 0%; transition: width 0.2s;
}

/* ===== HEADER ===== */
.site-header {
  position: sticky; top: 0;
  height: var(--header-h);
  background: rgba(13,15,26,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 500;
  transition: box-shadow 0.3s;
}
.site-header.scrolled { box-shadow: 0 4px 24px rgba(0,0,0,0.4); }

.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 20px; font-weight: 800;
  color: var(--text);
}
.logo-icon { font-size: 24px; }
.logo-text span { color: var(--accent); }

.main-nav { display: flex; align-items: center; gap: 8px; }
.nav-link {
  padding: 8px 16px; border-radius: 8px;
  font-size: 14px; font-weight: 600;
  color: var(--text-dim); transition: all 0.2s;
}
.nav-link:hover, .nav-link.active {
  background: var(--surface2); color: var(--text);
}

/* hamburger */
.hamburger {
  display: none; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 5px; width: 40px; height: 40px;
  border-radius: 8px; border: 1px solid var(--border);
  background: transparent; cursor: pointer;
}
.hamburger span {
  display: block; width: 18px; height: 2px;
  background: var(--text); border-radius: 2px;
  transition: all 0.3s;
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* mobile menu */
.mob-overlay {
  display: none; position: fixed; inset: 0;
  background: rgba(0,0,0,0.6); z-index: 400;
}
.mob-overlay.show { display: block; }

.mob-menu {
  position: fixed; top: var(--header-h); right: -260px;
  width: 260px; height: calc(100vh - var(--header-h));
  background: var(--surface);
  border-left: 1px solid var(--border);
  z-index: 450; padding: 24px 16px;
  display: flex; flex-direction: column; gap: 8px;
  transition: right 0.3s cubic-bezier(0.4,0,0.2,1);
  overflow-y: auto;
}
.mob-menu.open { right: 0; }
.mob-menu a {
  padding: 12px 16px; border-radius: 10px;
  font-size: 15px; font-weight: 600;
  color: var(--text-dim);
  transition: all 0.2s; display: block;
}
.mob-menu a:hover { background: var(--surface2); color: var(--text); }

/* ===== AD CONTAINERS ===== */
.ad-container {
  max-width: var(--max-w); margin: 0 auto;
  padding: 16px 24px; text-align: center;
}
.ad-label {
  font-size: 10px; color: var(--text-dim);
  letter-spacing: 1px; text-transform: uppercase;
  margin-bottom: 6px; font-weight: 600;
}
.ad-top { padding: 24px 24px 8px; }
.ad-mid { padding: 32px 24px; }
.ad-bottom { padding: 16px 24px 32px; }
/* AdSense responsive minimum height to avoid CLS */
.adsbygoogle { min-height: 90px; }

/* ===== SECTION COMMONS ===== */
.section { padding: 64px 0; }
.section-heading {
  font-size: clamp(22px, 4vw, 32px);
  font-weight: 800; margin-bottom: 8px;
  text-align: center;
}
.section-sub {
  color: var(--text-dim); text-align: center;
  margin-bottom: 40px; font-size: 16px;
  font-family: 'Tiro Devanagari Hindi', serif;
}

/* ===== HERO ===== */
.hero {
  padding: 80px 0 64px;
  text-align: center;
  background: radial-gradient(ellipse 80% 50% at 50% -10%, rgba(247,201,72,0.08), transparent);
  border-bottom: 1px solid var(--border);
}
.hero-badge {
  display: inline-block;
  background: rgba(74,222,128,0.12);
  color: var(--green);
  border: 1px solid rgba(74,222,128,0.3);
  padding: 6px 16px; border-radius: 20px;
  font-size: 13px; font-weight: 700;
  letter-spacing: 0.5px; margin-bottom: 24px;
}
.snake-emoji { font-size: clamp(56px, 10vw, 88px); display: block; margin-bottom: 8px; animation: float 3s ease-in-out infinite; }
@keyframes float { 0%,100%{transform:translateY(0)} 50%{transform:translateY(-10px)} }

.hero-title {
  font-size: clamp(32px, 7vw, 64px);
  font-weight: 800; line-height: 1.1;
  margin-bottom: 20px;
}
.gradient-text {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-sub {
  font-size: clamp(15px, 2.5vw, 18px);
  color: var(--text-dim);
  max-width: 560px; margin: 0 auto 32px;
  font-family: 'Tiro Devanagari Hindi', serif;
  line-height: 1.8;
}
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-bottom: 40px; }

.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 28px;
  background: var(--accent); color: #0d0f1a;
  border-radius: 10px; font-weight: 800; font-size: 15px;
  transition: all 0.2s; border: none; cursor: pointer;
}
.btn-primary:hover { background: #ffd86b; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(247,201,72,0.3); }

.btn-secondary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 28px;
  background: transparent; color: var(--text);
  border-radius: 10px; font-weight: 700; font-size: 15px;
  border: 1px solid var(--border); transition: all 0.2s;
}
.btn-secondary:hover { border-color: var(--accent2); color: var(--accent2); }

.btn-large { padding: 16px 36px; font-size: 17px; }

.hero-stats {
  display: flex; align-items: center;
  justify-content: center; gap: 24px;
  flex-wrap: wrap;
}
.stat { text-align: center; }
.stat strong { display: block; font-size: 28px; font-weight: 800; color: var(--accent); }
.stat span { font-size: 12px; color: var(--text-dim); font-weight: 600; }
.stat-divider { width: 1px; height: 40px; background: var(--border); }

/* ===== FEATURES ===== */
.features { background: var(--surface); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.feature-card {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 14px; padding: 24px;
  transition: all 0.2s;
}
.feature-card:hover { border-color: var(--accent2); transform: translateY(-3px); }
.fc-icon { font-size: 32px; margin-bottom: 12px; }
.feature-card h3 { font-size: 16px; font-weight: 700; margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--text-dim); line-height: 1.7; font-family: 'Tiro Devanagari Hindi', serif; }

/* ===== CHAPTERS GRID ===== */
.chapters-section { background: var(--bg); }
.chapters-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-bottom: 40px;
}
.chapter-card {
  display: flex; align-items: center; gap: 16px;
  padding: 18px 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: all 0.2s;
  color: var(--text);
}
.chapter-card:hover { border-color: var(--accent); background: var(--surface2); transform: translateX(4px); }
.ch-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px; font-weight: 700;
  color: var(--accent); min-width: 28px;
  background: rgba(247,201,72,0.1);
  padding: 4px 8px; border-radius: 6px;
}
.ch-info { flex: 1; }
.ch-info h3 { font-size: 15px; font-weight: 700; margin-bottom: 3px; }
.ch-info p { font-size: 12px; color: var(--text-dim); font-family: 'Tiro Devanagari Hindi', serif; }
.ch-badge {
  font-size: 10px; font-weight: 700;
  padding: 3px 8px; border-radius: 20px;
  white-space: nowrap; flex-shrink: 0;
}
.ch-badge.beginner { background: rgba(74,222,128,0.12); color: var(--green); }
.ch-badge.medium { background: rgba(247,201,72,0.12); color: var(--accent); }
.ch-badge.advanced { background: rgba(167,139,250,0.12); color: var(--accent3); }

.start-cta { text-align: center; }

/* ===== FAQ ===== */
.faq-section { background: var(--surface); border-top: 1px solid var(--border); }
.faq-list { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 12px; }
.faq-item {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 12px; overflow: hidden;
}
.faq-q {
  width: 100%; padding: 18px 20px;
  background: transparent; border: none;
  color: var(--text); font-size: 15px; font-weight: 700;
  text-align: left; cursor: pointer;
  display: flex; justify-content: space-between; align-items: center;
  font-family: 'Plus Jakarta Sans', sans-serif;
  transition: color 0.2s;
}
.faq-q:hover { color: var(--accent); }
.faq-arrow { font-size: 12px; color: var(--text-dim); transition: transform 0.3s; flex-shrink: 0; margin-left: 12px; }
.faq-item.open .faq-arrow { transform: rotate(180deg); }
.faq-a {
  max-height: 0; overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s;
}
.faq-item.open .faq-a { max-height: 200px; }
.faq-a p {
  padding: 0 20px 18px;
  color: var(--text-dim); font-size: 14px;
  line-height: 1.8;
  font-family: 'Tiro Devanagari Hindi', serif;
}

/* ===== FOOTER ===== */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 48px 0 24px;
}
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr;
  gap: 40px; margin-bottom: 40px;
}
.footer-logo { font-size: 20px; font-weight: 800; margin-bottom: 12px; }
.footer-brand p { font-size: 13px; color: var(--text-dim); line-height: 1.7; font-family: 'Tiro Devanagari Hindi', serif; }
.footer-links h4 { font-size: 13px; font-weight: 700; color: var(--accent); margin-bottom: 14px; letter-spacing: 0.5px; }
.footer-links a { display: block; font-size: 13px; color: var(--text-dim); margin-bottom: 10px; transition: color 0.2s; }
.footer-links a:hover { color: var(--text); }
.footer-bottom {
  border-top: 1px solid var(--border); padding-top: 24px;
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 8px;
}
.footer-bottom p { font-size: 13px; color: var(--text-dim); }

/* ===== CHAPTER PAGE LAYOUT ===== */
.chapter-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: calc(100vh - var(--header-h));
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  gap: 32px;
}

/* Chapter sidebar */
.ch-sidebar {
  padding: 32px 0;
  position: sticky; top: calc(var(--header-h) + 16px);
  height: calc(100vh - var(--header-h) - 32px);
  overflow-y: auto; align-self: start;
  scrollbar-width: thin; scrollbar-color: var(--border) transparent;
}
.ch-sidebar-title {
  font-size: 11px; font-weight: 700; letter-spacing: 2px;
  text-transform: uppercase; color: var(--text-dim);
  margin-bottom: 12px; padding: 0 8px;
}
.ch-nav-item {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 12px; border-radius: 8px;
  font-size: 13px; color: var(--text-dim);
  cursor: pointer; transition: all 0.2s;
  border: 1px solid transparent;
  text-decoration: none; margin-bottom: 2px;
}
.ch-nav-item:hover { background: var(--surface2); color: var(--text); }
.ch-nav-item.active { background: rgba(247,201,72,0.1); color: var(--accent); border-color: rgba(247,201,72,0.2); }
.ch-nav-item .cn-num { font-family: 'JetBrains Mono', monospace; font-size: 11px; min-width: 22px; }
.ch-nav-done { margin-left: auto; width: 7px; height: 7px; border-radius: 50%; background: var(--green); }

/* Chapter content */
.ch-content { padding: 40px 0 80px; min-width: 0; }
.ch-breadcrumb { font-size: 13px; color: var(--text-dim); margin-bottom: 24px; }
.ch-breadcrumb a { color: var(--accent2); }
.ch-breadcrumb a:hover { text-decoration: underline; }

.ch-header { margin-bottom: 40px; padding-bottom: 24px; border-bottom: 1px solid var(--border); }
.ch-label {
  display: inline-block; font-size: 11px; font-weight: 700;
  padding: 4px 10px; border-radius: 20px;
  background: rgba(79,195,247,0.12); color: var(--accent2);
  border: 1px solid rgba(79,195,247,0.25);
  font-family: 'JetBrains Mono', monospace; letter-spacing: 1px;
  margin-bottom: 12px;
}
.ch-title { font-size: clamp(24px, 4vw, 36px); font-weight: 800; margin-bottom: 8px; }
.ch-subtitle { font-size: 16px; color: var(--text-dim); font-family: 'Tiro Devanagari Hindi', serif; }

/* Sections */
.content-section { margin-bottom: 48px; }
.sec-title {
  font-size: 20px; font-weight: 700;
  margin-bottom: 16px;
  display: flex; align-items: center; gap: 10px;
}
.sec-title::before {
  content: ''; display: block;
  width: 4px; height: 22px;
  background: var(--accent); border-radius: 2px;
}

/* Explain box */
.explain {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent3);
  padding: 16px 20px; border-radius: 8px;
  margin-bottom: 20px;
  font-family: 'Tiro Devanagari Hindi', serif;
  font-size: 15px; line-height: 1.9; color: var(--text);
}

/* Tip / Warn */
.tip {
  background: rgba(74,222,128,0.06);
  border: 1px solid rgba(74,222,128,0.2);
  border-left: 3px solid var(--green);
  padding: 14px 18px; border-radius: 8px;
  margin: 16px 0; font-size: 14px;
  font-family: 'Tiro Devanagari Hindi', serif;
}
.tip strong { color: var(--green); font-family: 'Plus Jakarta Sans', sans-serif; }
.warn {
  background: rgba(248,113,113,0.06);
  border: 1px solid rgba(248,113,113,0.2);
  border-left: 3px solid var(--red);
  padding: 14px 18px; border-radius: 8px;
  margin: 16px 0; font-size: 14px;
  font-family: 'Tiro Devanagari Hindi', serif;
}
.warn strong { color: var(--red); font-family: 'Plus Jakarta Sans', sans-serif; }

/* Code block */
.code-block { background: var(--code-bg); border: 1px solid var(--border); border-radius: 10px; margin: 16px 0; overflow: hidden; }
.code-header {
  display: flex; justify-content: space-between; align-items: center;
  padding: 10px 16px;
  background: var(--surface2); border-bottom: 1px solid var(--border);
}
.code-lang { font-size: 11px; color: var(--accent2); font-family: 'JetBrains Mono', monospace; font-weight: 700; }
.copy-btn {
  font-size: 11px; padding: 4px 12px; border-radius: 4px;
  border: 1px solid var(--border); background: transparent;
  color: var(--text-dim); cursor: pointer; transition: all 0.2s;
  font-family: 'JetBrains Mono', monospace;
}
.copy-btn:hover { border-color: var(--accent); color: var(--accent); }
pre {
  padding: 20px; overflow-x: auto;
  font-family: 'JetBrains Mono', monospace;
  font-size: 13.5px; line-height: 1.7; color: #cdd6f4;
}
.kw { color: #cba6f7; }
.fn { color: #89b4fa; }
.st { color: #a6e3a1; }
.cm { color: #585b70; font-style: italic; }
.nm { color: #fab387; }
.cl { color: #f38ba8; }

/* Output */
.output-block {
  background: #050709; border: 1px solid #1a1f35;
  border-top: 2px solid var(--green);
  border-radius: 0 0 8px 8px;
  padding: 14px 20px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px; color: var(--green); margin-top: -8px;
}
.out-label { font-size: 10px; color: var(--text-dim); margin-bottom: 6px; letter-spacing: 1px; }

/* Table */
.data-table-wrap { overflow-x: auto; margin: 20px 0; -webkit-overflow-scrolling: touch; }
.data-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.data-table th {
  background: var(--surface2); padding: 12px 16px;
  text-align: left; font-weight: 700; color: var(--accent);
  border-bottom: 2px solid var(--border);
  font-family: 'JetBrains Mono', monospace; font-size: 12px;
}
.data-table td { padding: 10px 16px; border-bottom: 1px solid var(--border); }
.data-table tr:hover td { background: var(--surface2); }
.data-table code {
  background: var(--surface2); padding: 2px 6px;
  border-radius: 4px; font-family: 'JetBrains Mono', monospace;
  font-size: 12px; color: var(--accent2);
}

/* Grid 2 col */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin: 16px 0; }
.grid-card { background: var(--surface2); border: 1px solid var(--border); border-radius: 10px; padding: 16px; }
.grid-card h4 { font-size: 13px; color: var(--accent2); margin-bottom: 8px; font-family: 'JetBrains Mono', monospace; }
.grid-card p { font-size: 13px; color: var(--text-dim); font-family: 'Tiro Devanagari Hindi', serif; line-height: 1.7; }

/* Quiz */
.quiz-box {
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: 12px; padding: 24px; margin: 28px 0;
  border-top: 3px solid var(--accent3);
}
.quiz-box h3 { color: var(--accent3); font-size: 12px; font-weight: 800; margin-bottom: 12px; letter-spacing: 1.5px; }
.quiz-q { font-size: 16px; margin-bottom: 16px; font-family: 'Tiro Devanagari Hindi', serif; line-height: 1.8; }
.quiz-options { display: flex; flex-direction: column; gap: 8px; }
.quiz-opt {
  padding: 12px 16px; border-radius: 8px;
  border: 1px solid var(--border); cursor: pointer;
  transition: all 0.2s; font-size: 14px;
  background: transparent; color: var(--text);
  text-align: left; font-family: 'JetBrains Mono', monospace;
  min-height: 48px;
}
.quiz-opt:hover { border-color: var(--accent2); background: rgba(79,195,247,0.05); }
.quiz-opt.correct { border-color: var(--green); background: rgba(74,222,128,0.1); color: var(--green); }
.quiz-opt.wrong { border-color: var(--red); background: rgba(248,113,113,0.1); color: var(--red); }
.quiz-feedback { margin-top: 12px; font-size: 14px; display: none; font-family: 'Tiro Devanagari Hindi', serif; line-height: 1.6; }

/* Chapter nav buttons */
.ch-nav-btns { display: flex; gap: 12px; margin-top: 48px; padding-top: 28px; border-top: 1px solid var(--border); }
.ch-nav-btn {
  flex: 1; padding: 14px 20px; border-radius: 10px;
  border: 1px solid var(--border); cursor: pointer;
  font-size: 14px; font-weight: 700; transition: all 0.2s;
  background: transparent; color: var(--text); text-align: center;
  display: block; font-family: 'Plus Jakarta Sans', sans-serif;
}
.ch-nav-btn:hover { border-color: var(--accent2); color: var(--accent2); }
.ch-nav-btn.primary { background: var(--accent); color: #0d0f1a; border-color: var(--accent); }
.ch-nav-btn.primary:hover { background: #ffd86b; }

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .chapter-layout { grid-template-columns: 220px 1fr; }
}

@media (max-width: 768px) {
  .main-nav { display: none; }
  .hamburger { display: flex; }

  .features-grid { grid-template-columns: 1fr 1fr; }
  .chapters-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }

  .chapter-layout {
    grid-template-columns: 1fr;
    padding: 0 16px;
  }
  .ch-sidebar { display: none; }
  .ch-sidebar.mob-open {
    display: block;
    position: fixed; top: var(--header-h); left: 0;
    width: 280px; height: calc(100vh - var(--header-h));
    background: var(--surface); border-right: 1px solid var(--border);
    z-index: 450; padding: 20px 12px;
    overflow-y: auto;
  }
  .ch-content { padding: 24px 0 80px; }
  .ch-title { font-size: 24px; }

  .grid-2 { grid-template-columns: 1fr; }

  /* Mobile bottom bar for chapters */
  .mob-chapter-bar {
    display: flex !important;
  }
}

@media (max-width: 480px) {
  .hero { padding: 56px 0 48px; }
  .hero-stats { gap: 16px; }
  .stat strong { font-size: 22px; }
  .features-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-actions { flex-direction: column; align-items: center; }
  .btn-primary, .btn-secondary { width: 100%; max-width: 300px; justify-content: center; }
  pre { font-size: 12px; padding: 14px; }
  .ch-nav-btns { flex-direction: column; }
}

/* Mobile chapter bottom bar */
.mob-chapter-bar {
  display: none;
  position: fixed; bottom: 0; left: 0; right: 0;
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 10px 16px calc(10px + env(safe-area-inset-bottom, 0px));
  z-index: 200; gap: 8px;
}
.mob-chapter-bar a, .mob-chapter-bar button {
  flex: 1; padding: 10px;
  text-align: center; font-size: 13px; font-weight: 700;
  border-radius: 8px; border: 1px solid var(--border);
  background: transparent; color: var(--text-dim);
  cursor: pointer; font-family: 'Plus Jakarta Sans', sans-serif;
  transition: all 0.2s; display: block;
}
.mob-chapter-bar .bar-primary { background: var(--accent); color: #0d0f1a; border-color: var(--accent); }