/* ============================================================
   Revise Direct — Design System
   Smart. Fast. Exam-Ready.
   ============================================================ */

:root {
  /* Brand palette */
  --ink: #0f172a;          /* deep navy-blue for text/headings */
  --ink-soft: #475569;     /* secondary text */
  --bg: #ffffff;
  --bg-soft: #f1f5f9;      /* light section backgrounds */
  --accent: #0ea5a3;       /* teal — primary CTA */
  --accent-hover: #0c8f8d;
  --accent-soft: #e6f7f6;
  --navy: #1e3a8a;         /* secondary / dark accent */
  --gold: #f59e0b;
  --line: #e2e8f0;
  --danger: #dc2626;

  /* Type */
  --font-display: "Sora", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;

  /* Sizing / layout */
  --radius: 14px;
  --radius-lg: 20px;
  --container: 1120px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06), 0 1px 3px rgba(15, 23, 42, 0.08);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 12px 32px rgba(15, 23, 42, 0.12);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  color: var(--ink-soft);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--ink);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

img, svg { display: inline-block; vertical-align: middle; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }
.section { padding: 80px 0; }
.section-soft { background: var(--bg-soft); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 26px;
  border: none; border-radius: 12px;
  font-family: var(--font-display); font-weight: 600; font-size: 15px;
  cursor: pointer; transition: all 0.18s ease; text-decoration: none;
  line-height: 1.2;
}
.btn:not(:disabled):hover { transform: translateY(-2px); text-decoration: none; box-shadow: var(--shadow-md); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-accent { background: var(--accent); color: #fff; }
.btn-accent:hover { background: var(--accent-hover); }
.btn-navy { background: var(--navy); color: #fff; }
.btn-navy:hover { background: #172554; }
.btn-outline { background: transparent; color: var(--ink); border: 1.5px solid var(--line); }
.btn-outline:hover { border-color: var(--ink); }
.btn-white { background: #fff; color: var(--navy); }
.btn-block { width: 100%; }
.btn-lg { padding: 16px 34px; font-size: 16px; }
.btn-sm { padding: 9px 18px; font-size: 14px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,0.9);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  max-width: var(--container); margin: 0 auto; padding: 0 24px;
  height: 72px; display: flex; align-items: center; justify-content: space-between;
}
.brand { display: flex; align-items: center; text-decoration: none; gap: 10px; }
.brand:hover { text-decoration: none; }
.brand-mark {
  width: 38px; height: 38px; border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), var(--navy));
  display: grid; place-items: center; color: #fff; font-weight: 800;
  font-size: 19px; font-family: var(--font-display);
}
.brand-name { font-family: var(--font-display); font-weight: 700; font-size: 20px; color: var(--ink); }
.brand-name span { color: var(--accent); }
.brand-tag { display: block; font-size: 11px; font-weight: 500; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-soft); }

.nav { display: flex; align-items: center; gap: 28px; }
.nav a { color: var(--ink); font-weight: 500; font-size: 15px; }
.nav a:hover { color: var(--accent); text-decoration: none; }
.nav .btn { margin-left: 4px; }

.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--ink); margin: 5px 0; border-radius: 2px; transition: 0.3s; }

/* ---------- Hero ---------- */
.hero { position: relative; overflow: hidden;
  background: radial-gradient(1200px 600px at 80% -10%, var(--accent-soft), transparent 60%),
              radial-gradient(900px 500px at 0% 0%, #edf5ff, transparent 55%);
  padding: 90px 0 100px;
}
.hero-grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 48px; align-items: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-display); font-weight: 600; font-size: 13px;
  color: var(--accent); letter-spacing: 0.05em; text-transform: uppercase;
  background: var(--accent-soft); padding: 7px 14px; border-radius: 999px;
}
.hero h1 { font-size: clamp(38px, 5.4vw, 60px); margin: 22px 0 18px; }
.hero h1 .accent { color: var(--accent); }
.hero .lede { font-size: 18px; color: var(--ink-soft); max-width: 44ch; margin-bottom: 32px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 40px; margin-top: 44px; }
.stat .num { font-family: var(--font-display); font-weight: 800; font-size: 30px; color: var(--ink); }
.stat .lab { font-size: 14px; color: var(--ink-soft); }

/* Hero visual */
.hero-card {
  background: #fff; border-radius: var(--radius-lg); padding: 14px;
  box-shadow: var(--shadow-lg); border: 1px solid var(--line);
}
.hero-card img { width: 100%; border-radius: 12px; }
.hero-float {
  position: absolute; background: #fff; border-radius: 12px;
  box-shadow: var(--shadow-lg); padding: 12px 16px; font-size: 14px;
  display: flex; align-items: center; gap: 10px; border: 1px solid var(--line);
}
.hero-float .dot { width: 36px; height: 36px; border-radius: 9px; display: grid; place-items: center; }
.float-a { bottom: 40px; left: -24px; animation: bob 4s ease-in-out infinite; }
.float-b { top: 30px; right: -18px; animation: bob 4s ease-in-out 1.5s infinite; }
@keyframes bob { 0%,100%{transform:translateY(0)} 50%{transform:translateY(-8px)} }

.pill-row { display: flex; gap: 10px; flex-wrap: wrap; }
.pill { font-size: 13px; font-weight: 500; background: #fff; border: 1px solid var(--line);
  padding: 7px 13px; border-radius: 999px; color: var(--ink); box-shadow: var(--shadow-sm); }

/* ---------- Feature cards ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-top: 44px; }
.feature { background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; box-shadow: var(--shadow-sm); transition: all 0.2s ease; }
.feature:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.feature .icon { width: 46px; height: 46px; border-radius: 12px; display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent); margin-bottom: 16px; }
.feature h3 { font-size: 17px; margin-bottom: 8px; }
.feature p { font-size: 14.5px; }

/* ---------- Course cards ---------- */
.course-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; margin-top: 48px; }
.course-card {
  background: #fff; border-radius: var(--radius-lg); border: 1px solid var(--line);
  overflow: hidden; display: flex; flex-direction: column;
  box-shadow: var(--shadow-sm); transition: all 0.22s ease;
  position: relative;
}
.course-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); }
.course-head { padding: 26px 28px 6px; }
.badge {
  display: inline-block; font-family: var(--font-display); font-weight: 700; font-size: 12px;
  letter-spacing: 0.04em; text-transform: uppercase; padding: 5px 11px; border-radius: 999px;
}
.badge-bs { background: var(--gold); color: #fff; }
.badge-pop { background: var(--accent); color: #fff; }
.course-card h3 { font-size: 24px; margin: 16px 0 4px; }
.course-syllabus { font-size: 14px; font-weight: 600; color: var(--accent); }
.course-body { padding: 18px 28px 0; }
.course-body ul { list-style: none; }
.course-body li { display: flex; gap: 10px; align-items: flex-start; padding: 6px 0; font-size: 15px; }
.course-body li svg { margin-top: 3px; flex-shrink: 0; color: var(--accent); }
.course-foot { padding: 24px 28px 28px; margin-top: auto; }
.price-block { display: flex; align-items: baseline; gap: 8px; margin-bottom: 16px; }
.price-from { font-size: 14px; color: var(--ink-soft); }
.price-amt { font-family: var(--font-display); font-weight: 800; font-size: 30px; color: var(--ink); }
.price-unit { font-size: 14px; color: var(--ink-soft); }
.price-or { width: 100%; font-size: 14px; color: var(--ink-soft); margin-bottom: 14px; }
.price-or b { color: var(--accent); }

/* ---------- Section headings ---------- */
.sec-head { text-align: center; max-width: 640px; margin: 0 auto; }
.sec-head .kicker { font-family: var(--font-display); font-weight: 600; font-size: 13px;
  letter-spacing: 0.08em; text-transform: uppercase; color: var(--accent); }
.sec-head h2 { font-size: clamp(28px, 4vw, 38px); margin: 12px 0 12px; }
.sec-head p { font-size: 16.5px; }

/* ---------- Topic/unit cards (IGCSE) ---------- */
.unit-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-top: 44px; }
.unit-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; display: flex; flex-direction: column; box-shadow: var(--shadow-sm);
  transition: all 0.2s ease; }
.unit-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.unit-num { font-family: var(--font-display); font-weight: 800; font-size: 14px;
  color: var(--accent); letter-spacing: 0.05em; }
.unit-card h3 { font-size: 18px; margin: 8px 0 12px; }
.unit-card ul { list-style: none; margin-bottom: 18px; }
.unit-card li { display: flex; gap: 8px; font-size: 14px; padding: 4px 0; }
.unit-card li svg { color: var(--accent); flex-shrink: 0; margin-top: 2px; }
.unit-actions { margin-top: auto; }

.coming-soon {
  background: var(--bg-soft); border: 1px dashed var(--ink-soft);
  display: grid; place-items: center; text-align: center; color: var(--ink-soft);
}
.coming-soon .inner { padding: 30px; }
.coming-soon .cs-badge { font-family: var(--font-display); font-weight: 700; font-size: 12px;
  letter-spacing: 0.08em; text-transform: uppercase; color: var(--navy); }
.coming-soon h3 { color: var(--ink-soft); margin: 8px 0; }
.coming-soon p { font-size: 14px; }

/* ---------- AS Level catalog ---------- */
.catalog { margin-top: 48px; display: flex; flex-direction: column; gap: 18px; }
.topic { background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow-sm); }
.topic-head { display: flex; align-items: center; gap: 16px; padding: 20px 26px; cursor: pointer;
  transition: background 0.15s ease; }
.topic-head:hover { background: var(--bg-soft); }
.topic-idx { width: 40px; height: 40px; border-radius: 11px; display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent); font-family: var(--font-display);
  font-weight: 800; flex-shrink: 0; }
.topic-meta { flex: 1; }
.topic-meta .t-title { font-family: var(--font-display); font-weight: 700; font-size: 17px; color: var(--ink); }
.topic-meta .t-sub { font-size: 14px; color: var(--ink-soft); }
.topic-price { text-align: right; font-family: var(--font-display); font-weight: 800; font-size: 18px; color: var(--ink); }
.topic-price small { display: block; font-size: 12px; font-weight: 500; color: var(--ink-soft); font-family: var(--font-body); }
.topic-chev { color: var(--ink-soft); transition: transform 0.25s ease; flex-shrink: 0; }
.topic.open .topic-chev { transform: rotate(180deg); }
.topic-body { display: none; padding: 4px 26px 24px; border-top: 1px dashed var(--line); }
.topic.open .topic-body { display: block; }

.section-row { display: flex; align-items: center; gap: 16px; padding: 16px 0;
  border-bottom: 1px solid var(--line); }
.section-row:last-child { border-bottom: none; }
.section-row .s-title { flex: 1; font-weight: 500; color: var(--ink); font-size: 15px; }
.section-row .s-price { font-family: var(--font-display); font-weight: 700; color: var(--ink); margin-right: 10px; }
.topic-buy-top { display: inline-flex; align-items: center; }

/* ---------- Bundle CTA ---------- */
.bundle { background: linear-gradient(135deg, var(--navy) 0%, #0b1f4d 100%);
  color: #fff; border-radius: var(--radius-lg); padding: 56px;
  display: grid; grid-template-columns: 1.2fr 1fr; gap: 40px; align-items: center;
  box-shadow: var(--shadow-lg); }
.bundle h2 { color: #fff; font-size: clamp(26px, 3.4vw, 34px); margin-bottom: 16px; }
.bundle h2 .save { color: var(--gold); }
.bundle p { color: rgba(255,255,255,0.85); font-size: 16px; margin-bottom: 24px; }
.bundle ul { list-style: none; display: grid; grid-template-columns: 1fr 1fr; gap: 12px 20px; margin: 0 0 28px; }
.bundle li { display: flex; gap: 10px; align-items: flex-start; font-size: 15px; color: rgba(255,255,255,0.95); }
.bundle li svg { color: var(--gold); flex-shrink: 0; margin-top: 2px; }
.bundle-price { text-align: center; background: rgba(255,255,255,0.08); border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius); padding: 34px; }
.bundle-price .was { text-decoration: line-through; color: rgba(255,255,255,0.5); font-size: 16px; }
.bundle-price .now { font-family: var(--font-display); font-weight: 800; font-size: 52px; color: #fff; line-height: 1.1; }
.bundle-price .now small { font-size: 20px; }
.bundle-price .lab { font-size: 14px; color: rgba(255,255,255,0.7); margin: 6px 0 20px; }

/* ---------- Steps ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; margin-top: 44px; }
.step { text-align: center; padding: 30px 22px; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); }
.step .s-num { width: 44px; height: 44px; margin: 0 auto 16px; border-radius: 50%;
  background: var(--accent-soft); color: var(--accent); display: grid; place-items: center;
  font-family: var(--font-display); font-weight: 800; font-size: 18px; }
.step h3 { font-size: 17px; margin-bottom: 8px; }
.step p { font-size: 14.5px; }

/* ---------- FAQ ---------- */
.faq { max-width: 760px; margin: 44px auto 0; display: flex; flex-direction: column; gap: 12px; }
.faq-item { background: #fff; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.faq-q { width: 100%; text-align: left; background: none; border: none; cursor: pointer;
  padding: 20px 24px; font-family: var(--font-display); font-weight: 600; font-size: 16px;
  color: var(--ink); display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.faq-q svg { color: var(--ink-soft); transition: transform 0.25s; flex-shrink: 0; }
.faq-item.open .faq-q svg { transform: rotate(45deg); }
.faq-a { display: none; padding: 0 24px 20px; font-size: 15px; }
.faq-item.open .faq-a { display: block; }

/* ---------- CTA strip ---------- */
.cta-strip { text-align: center; background: linear-gradient(135deg, var(--accent), var(--navy)); color: #fff;
  border-radius: var(--radius-lg); padding: 60px 40px; }
.cta-strip h2 { color: #fff; font-size: clamp(26px, 3.6vw, 34px); margin-bottom: 14px; }
.cta-strip p { color: rgba(255,255,255,0.9); font-size: 16.5px; margin-bottom: 28px; max-width: 560px; margin-inline: auto; }

/* ---------- Contact / Page header ---------- */
.page-hero { padding: 64px 0 56px; background: radial-gradient(900px 380px at 70% -20%, var(--accent-soft), transparent 60%); }
.page-hero h1 { font-size: clamp(32px, 4.4vw, 46px); margin-bottom: 12px; }
.page-hero p { font-size: 17px; max-width: 56ch; }

.form-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md); padding: 36px; }
.field { margin-bottom: 20px; }
.field label { display: block; font-weight: 600; font-size: 14px; color: var(--ink); margin-bottom: 7px; }
.field label .req { color: var(--danger); }
.field input, .field textarea {
  width: 100%; padding: 13px 15px; border: 1.5px solid var(--line); border-radius: 11px;
  font-family: var(--font-body); font-size: 15px; color: var(--ink); background: #fff;
  transition: border-color 0.15s ease;
}
.field input:focus, .field textarea:focus, .field input:focus-visible, .field textarea:focus-visible {
  outline: none; border-color: var(--accent); }
.field textarea { min-height: 150px; resize: vertical; }

.contact-grid { display: grid; grid-template-columns: 1fr 0.9fr; gap: 40px; align-items: start; }
.contact-side .info-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; margin-bottom: 20px; box-shadow: var(--shadow-sm); }
.contact-side h3 { font-size: 17px; margin-bottom: 10px; display: flex; align-items: center; gap: 10px; }
.contact-side .info-card a { font-weight: 600; }
.note { background: var(--accent-soft); border: 1px solid #b9e7e5; color: #0b5d5b;
  border-radius: var(--radius); padding: 18px 20px; font-size: 14.5px; }
.note b { color: var(--accent-hover); }

.form-msg { display: none; margin-top: 16px; padding: 13px 16px; border-radius: 10px; font-size: 14.5px; }
.form-msg.ok { display: block; background: #e6f7ed; color: #11632c; border: 1px solid #b5e6c7; }
.form-msg.err { display: block; background: #fdeaea; color: #a11b1b; border: 1px solid #f3c1c1; }

/* ---------- Policies ---------- */
.policy { background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm); padding: 34px; margin-bottom: 24px; }
.policy h2 { font-size: 22px; margin-bottom: 16px; display: flex; align-items: center; gap: 12px; }
.policy h2 .ic { width: 40px; height: 40px; border-radius: 11px; background: var(--accent-soft);
  color: var(--accent); display: grid; place-items: center; flex-shrink: 0; }
.policy ul { margin-left: 20px; display: flex; flex-direction: column; gap: 9px; }
.policy li { font-size: 15.5px; }

/* ---------- Footer ---------- */
.site-footer { background: var(--ink); color: rgba(255,255,255,0.7); padding: 56px 0 34px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px; }
.footer-brand .brand-name { color: #fff; }
.footer-brand p { font-size: 14.5px; margin-top: 14px; max-width: 32ch; }
.footer-col h4 { color: #fff; font-size: 14px; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 16px; }
.footer-col a { display: block; color: rgba(255,255,255,0.7); padding: 5px 0; font-size: 15px; }
.footer-col a:hover { color: var(--accent); text-decoration: none; }
.social-row { display: flex; gap: 10px; margin-top: 18px; }
.social-row a { width: 38px; height: 38px; border-radius: 10px; background: rgba(255,255,255,0.1);
  display: grid; place-items: center; color: #fff; }
.social-row a:hover { background: var(--accent); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.12); margin-top: 44px; padding-top: 26px;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; font-size: 14px; }

/* ---------- Toast (cart-like confirm) ---------- */
@keyframes slideup { from{transform:translate(-50%,100%);opacity:0} to{transform:translate(-50%,0);opacity:1} }
.toast { position: fixed; left: 50%; bottom: 30px; transform: translate(-50%, 0);
  background: var(--ink); color: #fff; padding: 15px 22px; border-radius: 12px;
  font-size: 15px; font-weight: 500; box-shadow: var(--shadow-lg); z-index: 100;
  display: none; align-items: center; gap: 10px; max-width: 90vw; text-align: center;
  animation: slideup 0.3s ease; }
.toast .t-ic { color: #7ee0a0; }

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .hero-grid, .contact-grid, .bundle { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .unit-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .hero-float { display: none; }
}
@media (max-width: 760px) {
  .nav { display: none; position: absolute; top: 72px; left: 0; right: 0; background: #fff;
    flex-direction: column; align-items: flex-start; padding: 20px 24px; gap: 16px;
    border-bottom: 1px solid var(--line); box-shadow: var(--shadow-md); }
  .nav.open { display: flex; }
  .nav-toggle { display: block; }
  .course-grid, .unit-grid, .feature-grid, .footer-grid { grid-template-columns: 1fr; }
  .bundle { padding: 36px 26px; }
  .bundle ul { grid-template-columns: 1fr; }
  .hero { padding: 56px 0 64px; }
  .section { padding: 56px 0; }
  .topic-head { flex-wrap: wrap; }
  .topic-price { width: 100%; text-align: left; }
  .hero-stats { gap: 24px; }
  .bundle-price .now { font-size: 40px; }
}