/* ===== Course Platform — Design Refresh ===== */
:root {
  --dark:     #0c0e1a;
  --dark2:    #141629;
  --dark3:    #1c1f38;
  --indigo:   #6366f1;
  --indigo-d: #4f46e5;
  --amber:    #f59e0b;
  --teal:     #14b8a6;
  --white:    #ffffff;
  --offwhite: #f8f9ff;
  --border:   rgba(255,255,255,0.08);
  --border-lt:#e5e7eb;
  --text:     #111827;
  --muted:    #6b7280;
  --shadow:   0 20px 60px rgba(12,14,26,0.18);
  --radius:   16px;
  --trans:    250ms ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: system-ui, -apple-system, 'Segoe UI', sans-serif; background: var(--offwhite); color: var(--text); line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* NAV */
.navbar { position: fixed; top: 0; left: 0; right: 0; z-index: 100; background: rgba(12,14,26,0.95); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border); }
.nav-inner { max-width: 1200px; margin: auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; height: 66px; }
.nav-logo { font-size: 1.2rem; font-weight: 800; color: var(--white); letter-spacing: -0.03em; }
.nav-logo em { font-style: normal; color: var(--indigo); }
.nav-links { display: flex; gap: 28px; }
.nav-links a { font-size: 0.87rem; font-weight: 500; color: rgba(255,255,255,0.6); transition: color var(--trans); }
.nav-links a:hover, .nav-links a.active { color: var(--white); }
.nav-actions { display: flex; gap: 10px; align-items: center; }
.btn-signin { font-size: 0.85rem; font-weight: 600; color: rgba(255,255,255,0.7); padding: 8px 16px; border-radius: 8px; transition: color var(--trans); }
.btn-signin:hover { color: white; }
.btn-enroll { background: var(--indigo); color: white; font-weight: 700; font-size: 0.85rem; padding: 9px 20px; border-radius: 999px; transition: opacity var(--trans); }
.btn-enroll:hover { opacity: 0.85; }

/* HERO */
.hero { min-height: 100vh; background: var(--dark); padding: 100px 24px 80px; display: flex; align-items: center; position: relative; overflow: hidden; }
.hero::before { content: ''; position: absolute; inset: 0; background: radial-gradient(ellipse 70% 60% at 60% 40%, rgba(99,102,241,0.18) 0%, transparent 60%), radial-gradient(ellipse 40% 50% at 10% 80%, rgba(20,184,166,0.08) 0%, transparent 50%); }
.hero-inner { max-width: 1200px; margin: auto; width: 100%; display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; position: relative; z-index: 1; }
.hero-badge { display: inline-flex; align-items: center; gap: 8px; background: rgba(99,102,241,0.15); border: 1px solid rgba(99,102,241,0.3); color: #a5b4fc; font-size: 0.78rem; font-weight: 600; padding: 6px 14px; border-radius: 999px; margin-bottom: 18px; }
.hero h1 { font-size: clamp(2.2rem, 4vw, 3.4rem); font-weight: 800; color: var(--white); letter-spacing: -0.04em; line-height: 1.1; margin-bottom: 18px; }
.hero h1 em { font-style: normal; color: var(--indigo); }
.hero-sub { color: rgba(255,255,255,0.6); font-size: 1.05rem; max-width: 480px; margin-bottom: 32px; }
.hero-btns { display: flex; gap: 12px; flex-wrap: wrap; }
.btn-primary { display: inline-block; background: var(--indigo); color: white; font-weight: 700; font-size: 0.95rem; padding: 14px 28px; border-radius: 999px; transition: opacity var(--trans); border: none; cursor: pointer; }
.btn-primary:hover { opacity: 0.85; }
.btn-ghost { display: inline-block; background: transparent; color: white; font-weight: 600; font-size: 0.95rem; padding: 13px 28px; border-radius: 999px; border: 1.5px solid rgba(255,255,255,0.2); transition: border-color var(--trans); }
.btn-ghost:hover { border-color: rgba(255,255,255,0.5); }
.hero-stats { display: flex; gap: 32px; margin-top: 36px; }
.hstat strong { display: block; font-size: 1.6rem; font-weight: 800; color: var(--white); }
.hstat span { font-size: 0.8rem; color: rgba(255,255,255,0.45); }
.hero-visual { position: relative; }
.course-preview-card { background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1); border-radius: 20px; padding: 24px; backdrop-filter: blur(12px); }
.cp-thumb { height: 160px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 3rem; margin-bottom: 16px; }
.cp-badge { display: inline-block; font-size: 0.72rem; font-weight: 700; padding: 4px 10px; border-radius: 999px; background: rgba(99,102,241,0.2); color: #a5b4fc; margin-bottom: 10px; }
.cp-title { font-size: 1rem; font-weight: 700; color: white; margin-bottom: 6px; }
.cp-meta { font-size: 0.8rem; color: rgba(255,255,255,0.45); display: flex; gap: 12px; margin-bottom: 14px; }
.cp-progress { height: 4px; background: rgba(255,255,255,0.1); border-radius: 2px; overflow: hidden; margin-bottom: 6px; }
.cp-progress-bar { height: 100%; background: var(--indigo); border-radius: 2px; width: 68%; }
.cp-progress-label { font-size: 0.72rem; color: rgba(255,255,255,0.4); }
.floating-card { position: absolute; background: white; border-radius: 14px; padding: 12px 16px; box-shadow: var(--shadow); font-size: 0.82rem; font-weight: 600; display: flex; align-items: center; gap: 8px; }
.fc-1 { top: -16px; right: -16px; }
.fc-2 { bottom: -16px; left: -16px; }

/* SECTION WRAPPER */
.section { padding: clamp(64px, 8vw, 96px) 24px; }
.section-inner { max-width: 1200px; margin: auto; }
.section-hdr { text-align: center; max-width: 640px; margin: 0 auto 52px; }
.eyebrow { display: inline-block; font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.12em; color: var(--indigo); margin-bottom: 10px; }
.section-hdr h2 { font-size: clamp(1.8rem, 3vw, 2.6rem); font-weight: 800; letter-spacing: -0.03em; margin-bottom: 12px; }
.section-hdr p { color: var(--muted); }

/* CATEGORIES */
.cat-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 16px; }
.cat-card { background: white; border-radius: var(--radius); padding: 24px 20px; text-align: center; box-shadow: 0 4px 20px rgba(0,0,0,0.06); border: 1px solid var(--border-lt); transition: transform var(--trans), box-shadow var(--trans); cursor: pointer; }
.cat-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.cat-icon { font-size: 2rem; margin-bottom: 10px; }
.cat-card h3 { font-size: 0.95rem; font-weight: 700; margin-bottom: 4px; }
.cat-card p { font-size: 0.8rem; color: var(--muted); }

/* COURSE CARDS */
.courses-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 24px; }
.course-card { background: white; border-radius: var(--radius); overflow: hidden; box-shadow: 0 4px 20px rgba(0,0,0,0.06); border: 1px solid var(--border-lt); transition: transform var(--trans), box-shadow var(--trans); }
.course-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.cc-thumb { height: 180px; display: flex; align-items: center; justify-content: center; font-size: 3.5rem; position: relative; }
.cc-badge { position: absolute; top: 12px; left: 12px; font-size: 0.7rem; font-weight: 700; padding: 4px 10px; border-radius: 999px; }
.badge-best { background: #fef3c7; color: #92400e; }
.badge-new { background: #ede9fe; color: #5b21b6; }
.badge-hot { background: #fee2e2; color: #991b1b; }
.cc-body { padding: 20px; }
.cc-category { font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--indigo); margin-bottom: 6px; }
.cc-body h3 { font-size: 1rem; font-weight: 700; margin-bottom: 6px; letter-spacing: -0.01em; }
.cc-instructor { font-size: 0.82rem; color: var(--muted); margin-bottom: 10px; }
.cc-rating { display: flex; align-items: center; gap: 6px; font-size: 0.82rem; margin-bottom: 12px; }
.cc-rating .star { color: var(--amber); }
.cc-footer { display: flex; justify-content: space-between; align-items: center; padding-top: 12px; border-top: 1px solid var(--border-lt); }
.cc-price { font-size: 1.1rem; font-weight: 800; color: var(--indigo); }
.cc-price del { font-size: 0.82rem; color: var(--muted); font-weight: 400; }
.btn-enroll-sm { background: var(--dark2); color: white; font-size: 0.8rem; font-weight: 700; padding: 8px 16px; border-radius: 999px; border: none; cursor: pointer; transition: background var(--trans); }
.btn-enroll-sm:hover { background: var(--indigo); }

/* DARK SECTION */
.dark-section { background: var(--dark); padding: clamp(64px, 8vw, 96px) 24px; }
.dark-section .section-hdr h2, .dark-section h2 { color: white; }
.dark-section p { color: rgba(255,255,255,0.6); }
.dark-section .eyebrow { color: rgba(99,102,241,0.8); }

/* FEATURES */
.features-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; }
.feature-list { display: flex; flex-direction: column; gap: 20px; }
.feat-item { display: flex; gap: 14px; }
.feat-icon { width: 44px; height: 44px; border-radius: 12px; background: rgba(99,102,241,0.15); display: flex; align-items: center; justify-content: center; font-size: 1.1rem; flex-shrink: 0; }
.feat-item h4 { font-size: 0.95rem; font-weight: 700; color: white; margin-bottom: 4px; }
.feat-item p { font-size: 0.87rem; color: rgba(255,255,255,0.55); }
.features-visual { background: rgba(255,255,255,0.04); border: 1px solid var(--border); border-radius: 20px; padding: 28px; }
.fv-stat { display: flex; justify-content: space-between; align-items: center; padding: 14px 0; border-bottom: 1px solid rgba(255,255,255,0.06); }
.fv-stat:last-child { border-bottom: none; }
.fv-label { font-size: 0.85rem; color: rgba(255,255,255,0.5); }
.fv-val { font-size: 1rem; font-weight: 700; color: white; }

/* STATS */
.stats-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px; }
.stat-box { text-align: center; }
.stat-box strong { display: block; font-size: 2.8rem; font-weight: 800; color: white; letter-spacing: -0.04em; line-height: 1; }
.stat-box strong em { font-style: normal; color: var(--indigo); }
.stat-box span { font-size: 0.85rem; color: rgba(255,255,255,0.45); display: block; margin-top: 6px; }

/* INSTRUCTORS */
.inst-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 24px; }
.inst-card { background: white; border-radius: var(--radius); overflow: hidden; box-shadow: 0 4px 20px rgba(0,0,0,0.06); border: 1px solid var(--border-lt); text-align: center; }
.inst-photo { height: 160px; display: flex; align-items: center; justify-content: center; font-size: 3rem; }
.inst-body { padding: 18px; }
.inst-body h4 { font-size: 0.98rem; font-weight: 700; margin-bottom: 3px; }
.inst-role { font-size: 0.78rem; color: var(--indigo); font-weight: 600; display: block; margin-bottom: 6px; }
.inst-body p { font-size: 0.82rem; color: var(--muted); }
.inst-rating { font-size: 0.8rem; color: var(--amber); margin-top: 8px; }

/* TESTIMONIALS */
.reviews-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 24px; }
.review-card { background: rgba(255,255,255,0.04); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.rev-stars { color: var(--amber); font-size: 0.88rem; margin-bottom: 12px; }
.review-card p { font-style: italic; color: rgba(255,255,255,0.65); font-size: 0.9rem; margin-bottom: 16px; }
.rev-author { display: flex; align-items: center; gap: 10px; }
.rev-avatar { width: 38px; height: 38px; border-radius: 50%; background: var(--dark3); display: flex; align-items: center; justify-content: center; font-size: 1rem; }
.rev-author h5 { font-size: 0.87rem; font-weight: 700; color: white; margin-bottom: 1px; }
.rev-author span { font-size: 0.75rem; color: rgba(255,255,255,0.4); }

/* CTA */
.cta-section { background: linear-gradient(135deg, var(--indigo-d), var(--indigo)); padding: 80px 24px; text-align: center; }
.cta-section h2 { font-size: clamp(1.9rem, 3.5vw, 2.8rem); font-weight: 800; color: white; letter-spacing: -0.03em; margin-bottom: 14px; }
.cta-section p { color: rgba(255,255,255,0.75); max-width: 460px; margin: 0 auto 32px; }
.btn-white { background: white; color: var(--indigo-d); font-weight: 800; font-size: 1rem; padding: 14px 32px; border-radius: 999px; display: inline-block; transition: opacity var(--trans); }
.btn-white:hover { opacity: 0.9; }

/* FOOTER */
footer { background: var(--dark); padding: 48px 24px 28px; }
.footer-inner { max-width: 1200px; margin: auto; }
.footer-top { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 36px; border-bottom: 1px solid var(--border); }
.footer-brand p { color: rgba(255,255,255,0.4); font-size: 0.87rem; margin-top: 10px; max-width: 240px; }
.footer-col h4 { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.1em; color: rgba(255,255,255,0.3); margin-bottom: 12px; }
.footer-col a { display: block; font-size: 0.87rem; color: rgba(255,255,255,0.5); margin-bottom: 8px; transition: color var(--trans); }
.footer-col a:hover { color: white; }
.footer-bottom { padding-top: 22px; display: flex; justify-content: space-between; font-size: 0.82rem; color: rgba(255,255,255,0.3); }

/* PAGE HERO (subpages) */
.page-hero { background: var(--dark); padding: 110px 24px 60px; text-align: center; color: white; }
.page-hero .breadcrumb { font-size: 0.8rem; color: rgba(255,255,255,0.35); margin-bottom: 14px; }
.page-hero .breadcrumb a { color: var(--indigo); }
.page-hero h1 { font-size: clamp(2rem, 4vw, 3.2rem); font-weight: 800; letter-spacing: -0.03em; margin-bottom: 12px; }
.page-hero p { color: rgba(255,255,255,0.6); max-width: 520px; margin: auto; }

/* REVEAL */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.55s ease, transform 0.55s ease; }
.reveal.visible { opacity: 1; transform: none; }

@media(max-width: 900px) {
  .hero-inner, .features-grid { grid-template-columns: 1fr; }
  .hero-visual { display: none; }
  .stats-row { grid-template-columns: repeat(2, 1fr); }
  .footer-top { grid-template-columns: 1fr 1fr; }
}
@media(max-width: 600px) {
  .nav-links { display: none; }
  .stats-row { grid-template-columns: 1fr 1fr; }
  .footer-top { grid-template-columns: 1fr; }
}