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

:root {
  --ink: #0a0a0f;
  --ink-2: #1c1c28;
  --muted: #6b6b85;
  --surface: #f4f3f8;
  --surface-2: #eceaf4;
  --white: #ffffff;
  --accent: #5b4cf5;
  --accent-2: #7c6ff7;
  --accent-glow: rgba(91,76,245,.12);
  --teal: #00c9a7;
  --teal-dim: rgba(0,201,167,.12);
  --amber: #f59e0b;
  --amber-dim: rgba(245,158,11,.12);
  --rose: #f43f5e;
  --rose-dim: rgba(244,63,94,.12);
  --border: rgba(0,0,0,.07);
  --border-2: rgba(0,0,0,.12);
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 1px 3px rgba(0,0,0,.04), 0 4px 16px rgba(0,0,0,.06);
  --shadow-lg: 0 2px 8px rgba(0,0,0,.04), 0 16px 48px rgba(0,0,0,.10);
}

html { scroll-behavior: smooth; }
body { font-family: 'DM Sans', sans-serif; background: var(--white); color: var(--ink); font-size: 15px; line-height: 1.65; overflow-x: hidden; }
h1,h2,h3,h4 { font-family: 'Syne', sans-serif; letter-spacing: -.02em; line-height: 1.15; }

/* ── NAVBAR ── */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 0 48px; height: 64px;
  display: flex; align-items: center; justify-content: space-between;
  background: rgba(255,255,255,.88); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-logo {
  font-family: 'Syne', sans-serif; font-weight: 800; font-size: 20px;
  color: var(--ink); text-decoration: none; cursor: pointer;
  display: flex; align-items: center; gap: 8px;
}
.nav-logo-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); }
.nav-links { display: flex; align-items: center; gap: 32px; list-style: none; }
.nav-links a { color: var(--muted); text-decoration: none; font-size: 14px; font-weight: 500; cursor: pointer; transition: color .2s; }
.nav-links a:hover { color: var(--ink); }
#nav-user { display: flex; align-items: center; gap: 12px; }
#nav-username { font-size: 14px; color: var(--muted); }

/* ── BUTTONS ── */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 20px; border-radius: var(--radius);
  font-family: 'DM Sans', sans-serif; font-weight: 500; font-size: 14px;
  cursor: pointer; text-decoration: none; transition: all .2s; border: none;
}
.btn-ghost { background: transparent; color: var(--muted); border: 1.5px solid var(--border-2); }
.btn-ghost:hover { background: var(--surface); color: var(--ink); }
.btn-primary { background: var(--ink); color: var(--white); }
.btn-primary:hover { background: var(--ink-2); transform: translateY(-1px); }
.btn-accent { background: var(--accent); color: var(--white); }
.btn-accent:hover { background: var(--accent-2); transform: translateY(-1px); box-shadow: 0 8px 24px rgba(91,76,245,.35); }
.btn-lg { padding: 14px 28px; font-size: 15px; border-radius: 14px; }
.btn-sm { padding: 7px 14px; font-size: 13px; }
.btn-danger { background: var(--rose); color: var(--white); }

/* ── MODAL ── */
.modal-overlay {
  position: fixed; inset: 0; background: rgba(0,0,0,.5);
  z-index: 200; display: none; align-items: center; justify-content: center;
  backdrop-filter: blur(4px);
}
.modal-overlay.open { display: flex; }
.modal {
  background: var(--white); border-radius: var(--radius-lg);
  padding: 36px; width: 100%; max-width: 440px;
  box-shadow: var(--shadow-lg); position: relative;
}
.modal-title { font-family: 'Syne', sans-serif; font-size: 22px; font-weight: 800; margin-bottom: 6px; }
.modal-sub { color: var(--muted); font-size: 14px; margin-bottom: 24px; }
.modal-close { position: absolute; top: 16px; right: 16px; background: none; border: none; cursor: pointer; color: var(--muted); font-size: 18px; }
.form-group { margin-bottom: 16px; }
.form-label { font-size: 13px; font-weight: 500; color: var(--ink-2); display: block; margin-bottom: 6px; }
.form-input { width: 100%; padding: 11px 14px; border: 1.5px solid var(--border-2); border-radius: var(--radius); font-family: 'DM Sans', sans-serif; font-size: 14px; outline: none; transition: border .2s; }
.form-input:focus { border-color: var(--accent); }
.form-error { color: var(--rose); font-size: 13px; margin-top: 8px; display: none; }
.form-error.visible { display: block; }

/* ── HERO ── */
.hero {
  min-height: 100vh; padding: 120px 48px 80px;
  display: flex; flex-direction: column; align-items: center;
  justify-content: center; text-align: center; position: relative; overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0;
  background: radial-gradient(ellipse 60% 50% at 50% 0%, rgba(91,76,245,.08) 0%, transparent 70%),
              radial-gradient(ellipse 40% 30% at 20% 60%, rgba(0,201,167,.06) 0%, transparent 60%);
  z-index: 0;
}
.hero-grid {
  position: absolute; inset: 0;
  background-image: linear-gradient(rgba(91,76,245,.04) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(91,76,245,.04) 1px, transparent 1px);
  background-size: 60px 60px; z-index: 0;
}
.hero-content { position: relative; z-index: 1; max-width: 820px; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 14px 6px 8px; background: var(--accent-glow);
  border: 1px solid rgba(91,76,245,.2); border-radius: 100px;
  font-size: 13px; font-weight: 500; color: var(--accent); margin-bottom: 28px;
}
.hero-badge-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); animation: pulse 2s infinite; }
@keyframes pulse { 0%,100%{opacity:1;transform:scale(1)} 50%{opacity:.5;transform:scale(.8)} }
.hero-title { font-size: clamp(36px,5.5vw,68px); font-weight: 800; color: var(--ink); margin-bottom: 20px; }
.hero-title-accent { color: var(--accent); }
.hero-sub { font-size: 17px; color: var(--muted); max-width: 520px; margin: 0 auto 40px; line-height: 1.7; font-weight: 300; }
.hero-actions { display: flex; align-items: center; justify-content: center; gap: 12px; flex-wrap: wrap; margin-bottom: 64px; }
.hero-stats { display: flex; align-items: center; gap: 40px; justify-content: center; flex-wrap: wrap; }
.hero-stat { text-align: center; }
.hero-stat-num { font-family: 'Syne', sans-serif; font-size: 26px; font-weight: 800; color: var(--ink); display: block; }
.hero-stat-label { font-size: 13px; color: var(--muted); }
.hero-divider { width: 1px; height: 36px; background: var(--border-2); }

/* ── SECTIONS ── */
.section { padding: 96px 48px; }
.section-inner { max-width: 1100px; margin: 0 auto; }
.section-tag { display: inline-flex; align-items: center; gap: 6px; font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: .1em; color: var(--accent); margin-bottom: 14px; }
.section-tag::before { content: ''; display: block; width: 16px; height: 2px; background: var(--accent); border-radius: 1px; }
.section-title { font-size: clamp(26px,3vw,40px); font-weight: 800; color: var(--ink); margin-bottom: 14px; }
.section-sub { font-size: 16px; color: var(--muted); max-width: 500px; line-height: 1.7; font-weight: 300; }

/* ── FEATURES ── */
.features-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 20px; margin-top: 48px; }
.feature-card { background: var(--white); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 28px; transition: box-shadow .25s, transform .25s; position: relative; overflow: hidden; }
.feature-card::before { content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px; background: var(--accent); opacity: 0; transition: opacity .25s; }
.feature-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); }
.feature-card:hover::before { opacity: 1; }
.feature-icon { width: 44px; height: 44px; border-radius: 12px; display: flex; align-items: center; justify-content: center; margin-bottom: 16px; font-size: 20px; }
.feature-icon-purple { background: var(--accent-glow); }
.feature-icon-teal { background: var(--teal-dim); }
.feature-icon-amber { background: var(--amber-dim); }
.feature-icon-rose { background: var(--rose-dim); }
.feature-title { font-family: 'Syne', sans-serif; font-size: 16px; font-weight: 700; color: var(--ink); margin-bottom: 8px; }
.feature-desc { font-size: 14px; color: var(--muted); line-height: 1.65; }

/* ── COURSES ── */
.courses-header { display: flex; align-items: flex-end; justify-content: space-between; margin-bottom: 32px; gap: 20px; flex-wrap: wrap; }
.chip-row { display: flex; gap: 8px; flex-wrap: wrap; }
.chip { padding: 6px 16px; border-radius: 100px; font-size: 13px; font-weight: 500; border: 1.5px solid var(--border-2); background: var(--white); color: var(--muted); cursor: pointer; transition: all .2s; }
.chip:hover { background: var(--surface); }
.chip.active { background: var(--accent); color: var(--white); border-color: var(--accent); }
.courses-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px,1fr)); gap: 20px; }
.course-card { background: var(--white); border: 1px solid var(--border); border-radius: var(--radius-lg); overflow: hidden; transition: box-shadow .25s, transform .25s; cursor: pointer; }
.course-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.course-thumb { height: 130px; display: flex; align-items: center; justify-content: center; font-size: 48px; }
.course-thumb-purple { background: linear-gradient(135deg,#ede9fe,#c4b5fd); }
.course-thumb-teal   { background: linear-gradient(135deg,#ccfbf1,#5eead4); }
.course-thumb-amber  { background: linear-gradient(135deg,#fef3c7,#fcd34d); }
.course-thumb-blue   { background: linear-gradient(135deg,#dbeafe,#93c5fd); }
.course-thumb-green  { background: linear-gradient(135deg,#dcfce7,#86efac); }
.course-thumb-rose   { background: linear-gradient(135deg,#ffe4e6,#fda4af); }
.course-body { padding: 18px; }
.course-tag { font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: .08em; color: var(--accent); margin-bottom: 6px; display: block; }
.course-name { font-family: 'Syne', sans-serif; font-size: 15px; font-weight: 700; color: var(--ink); margin-bottom: 8px; }
.course-meta { font-size: 13px; color: var(--muted); display: flex; gap: 14px; }

/* ── MENTORS ── */
.mentors-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px,1fr)); gap: 20px; margin-top: 40px; }
.mentor-card { background: var(--white); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 24px; text-align: center; transition: box-shadow .25s, transform .25s; }
.mentor-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); }
.mentor-avatar { width: 68px; height: 68px; border-radius: 50%; margin: 0 auto 14px; display: flex; align-items: center; justify-content: center; font-family: 'Syne', sans-serif; font-size: 22px; font-weight: 800; color: var(--white); }
.mentor-name { font-family: 'Syne', sans-serif; font-size: 15px; font-weight: 700; color: var(--ink); margin-bottom: 4px; }
.mentor-role { font-size: 13px; color: var(--muted); margin-bottom: 12px; }
.mentor-rating { font-size: 13px; color: var(--amber); font-weight: 600; }

/* ── PRICING ── */
.pricing-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 24px; margin-top: 48px; }
.pricing-card { background: var(--white); border: 1.5px solid var(--border); border-radius: var(--radius-lg); padding: 32px; transition: box-shadow .25s, transform .25s; position: relative; }
.pricing-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.pricing-card.featured { border-color: var(--accent); }
.pricing-badge { position: absolute; top: -14px; left: 50%; transform: translateX(-50%); background: var(--accent); color: var(--white); padding: 4px 16px; border-radius: 100px; font-size: 12px; font-weight: 600; }
.pricing-plan { font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: .1em; color: var(--accent); margin-bottom: 10px; }
.pricing-price { font-family: 'Syne', sans-serif; font-size: 40px; font-weight: 800; color: var(--ink); margin-bottom: 4px; }
.pricing-period { font-size: 13px; color: var(--muted); margin-bottom: 20px; }
.pricing-features { list-style: none; margin-bottom: 28px; display: flex; flex-direction: column; gap: 10px; }
.pricing-features li { font-size: 14px; display: flex; align-items: center; gap: 8px; }
.pricing-features li::before { content: '✓'; color: var(--teal); font-weight: 700; }

/* ── FOOTER ── */
footer { background: var(--surface); padding: 40px 48px; border-top: 1px solid var(--border); }
.footer-inner { max-width: 1100px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 20px; flex-wrap: wrap; }
.footer-copy { font-size: 13px; color: var(--muted); }

/* ── LOADING ── */
.loading-state { display: flex; align-items: center; justify-content: center; padding: 60px; flex-direction: column; gap: 16px; color: var(--muted); font-size: 14px; }
.spinner { width: 24px; height: 24px; border: 3px solid var(--border-2); border-top-color: var(--accent); border-radius: 50%; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ── TOAST ── */
#toast-container { position: fixed; bottom: 24px; right: 24px; z-index: 9999; display: flex; flex-direction: column; gap: 10px; }
.toast { background: var(--ink); color: var(--white); padding: 12px 20px; border-radius: var(--radius); font-size: 14px; box-shadow: var(--shadow-lg); animation: slideUp .3s ease; max-width: 300px; }
.toast.success { background: #059669; }
.toast.error { background: var(--rose); }
@keyframes slideUp { from{transform:translateY(20px);opacity:0} to{transform:translateY(0);opacity:1} }

/* ── EMPTY STATE ── */
.empty-state { text-align: center; padding: 60px 24px; color: var(--muted); }
.empty-state-icon { font-size: 44px; margin-bottom: 14px; }
.empty-state-text { font-size: 15px; }