:root {
  --bsm-bg: #f5f7fb;
  --bsm-card: #ffffff;
  --bsm-text: #101827;
  --bsm-muted: #667085;
  --bsm-line: rgba(16, 24, 39, .10);
  --bsm-primary: #1f4fff;
  --bsm-primary-dark: #1234b8;
  --bsm-accent: #00d4a6;
  --bsm-dark: #0d1324;
  --bsm-radius: 24px;
  --bsm-shadow: 0 22px 70px rgba(15, 23, 42, .11);
}
.bsm-shell { max-width: 1180px; margin: 0 auto; padding: 28px 18px; color: var(--bsm-text); font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; }
.bsm-shell * { box-sizing: border-box; }
.bsm-shell a { color: inherit; text-decoration: none; }
.bsm-section-heading { text-align: center; margin-bottom: 28px; }
.bsm-section-heading.left { text-align: left; }
.bsm-section-heading h2, .bsm-dashboard-hero h2, .bsm-course-hero h2 { font-size: clamp(30px, 4vw, 52px); line-height: 1.04; margin: 8px 0 12px; letter-spacing: -0.04em; }
.bsm-section-heading p, .bsm-dashboard-hero p, .bsm-course-hero p { color: var(--bsm-muted); font-size: 17px; line-height: 1.65; max-width: 720px; }
.bsm-kicker { display: inline-flex; align-items: center; gap: 8px; text-transform: uppercase; letter-spacing: .12em; font-weight: 800; font-size: 12px; color: var(--bsm-primary); }
.bsm-kicker:before { content: ""; width: 9px; height: 9px; border-radius: 99px; background: var(--bsm-accent); box-shadow: 0 0 0 6px rgba(0,212,166,.12); }
.bsm-panel, .bsm-course-card, .bsm-empty-state, .bsm-alert, .bsm-lock-box, .bsm-quiz, .bsm-materials { background: var(--bsm-card); border: 1px solid var(--bsm-line); border-radius: var(--bsm-radius); box-shadow: var(--bsm-shadow); }
.bsm-btn { display: inline-flex; align-items: center; justify-content: center; border: 0; border-radius: 999px; padding: 13px 20px; min-height: 46px; font-weight: 800; cursor: pointer; transition: transform .18s ease, box-shadow .18s ease, opacity .18s ease; text-decoration: none !important; }
.bsm-btn:hover { transform: translateY(-1px); }
.bsm-btn[disabled] { opacity: .65; cursor: not-allowed; }
.bsm-btn-primary { color: white !important; background: linear-gradient(135deg, var(--bsm-primary), var(--bsm-primary-dark)); box-shadow: 0 12px 28px rgba(31,79,255,.24); }
.bsm-btn-light { color: var(--bsm-dark) !important; background: white; }
.bsm-chip { display: inline-flex; align-items: center; gap: 6px; padding: 7px 11px; border-radius: 999px; background: rgba(31,79,255,.09); color: var(--bsm-primary); font-size: 12px; font-weight: 800; }
.bsm-meta-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; color: var(--bsm-muted); font-size: 14px; margin: 14px 0; }
.bsm-auth-grid { display: grid; grid-template-columns: minmax(0, 1fr) 430px; gap: 22px; align-items: stretch; }
.bsm-panel { padding: 28px; }
.bsm-gradient-panel { min-height: 430px; display: flex; flex-direction: column; justify-content: flex-end; background: radial-gradient(circle at top left, rgba(0,212,166,.55), transparent 34%), linear-gradient(135deg, #101827, #172554 58%, #1f4fff); color: white; overflow: hidden; position: relative; }
.bsm-gradient-panel:after { content: ""; position: absolute; width: 260px; height: 260px; border-radius: 50%; right: -90px; top: -80px; border: 34px solid rgba(255,255,255,.10); }
.bsm-gradient-panel .bsm-kicker, .bsm-gradient-panel p { color: rgba(255,255,255,.78); }
.bsm-gradient-panel h2 { font-size: clamp(34px, 5vw, 58px); line-height: 1; letter-spacing: -0.05em; margin: 12px 0; }
.bsm-tabs { display: grid; grid-template-columns: 1fr 1fr; background: var(--bsm-bg); border-radius: 999px; padding: 5px; margin-bottom: 20px; }
.bsm-tab { border: 0; background: transparent; border-radius: 999px; padding: 12px; font-weight: 800; cursor: pointer; color: var(--bsm-muted); }
.bsm-tab.is-active { color: var(--bsm-text); background: white; box-shadow: 0 8px 24px rgba(15,23,42,.10); }
.bsm-tab-panel { display: none; }
.bsm-tab-panel.is-active { display: grid; gap: 14px; }
.bsm-form { display: grid; gap: 14px; }
.bsm-form label { display: grid; gap: 7px; font-weight: 700; font-size: 14px; }
.bsm-form input, .bsm-form textarea, .bsm-form select { width: 100%; border: 1px solid var(--bsm-line); border-radius: 16px; padding: 13px 14px; background: white; color: var(--bsm-text); min-height: 46px; }
.bsm-form-message { margin-top: 10px; font-weight: 700; color: var(--bsm-primary); }
.bsm-form-message.is-error { color: #d92d20; }
.bsm-form-message.is-success { color: #047857; }
.bsm-dashboard-hero, .bsm-course-hero { display: grid; grid-template-columns: minmax(0,1fr) 300px; gap: 22px; align-items: center; padding: 34px; border-radius: 32px; background: linear-gradient(135deg, #101827, #1e3a8a); color: white; margin-bottom: 28px; overflow: hidden; }
.bsm-dashboard-hero p, .bsm-course-hero p, .bsm-course-hero .bsm-meta-row { color: rgba(255,255,255,.78); }
.bsm-teacher-actions { display: flex; flex-wrap: wrap; gap: 10px; margin: -8px 0 28px; }
.bsm-course-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 22px; }
.bsm-course-card { overflow: hidden; display: flex; flex-direction: column; min-height: 100%; }
.bsm-card-media { min-height: 180px; background: radial-gradient(circle at 20% 20%, rgba(0,212,166,.55), transparent 35%), linear-gradient(135deg, #111827, #1f4fff); background-position: center; background-size: cover; color: white; display: grid; place-items: center; font-weight: 900; font-size: 28px; letter-spacing: -0.05em; }
.bsm-card-body { padding: 20px; display: grid; gap: 10px; flex: 1; }
.bsm-card-body h3 { margin: 4px 0 0; font-size: 22px; line-height: 1.18; letter-spacing: -0.02em; }
.bsm-card-body p { color: var(--bsm-muted); line-height: 1.55; margin: 0; }
.bsm-progress { height: 9px; background: rgba(16,24,39,.08); overflow: hidden; border-radius: 99px; }
.bsm-progress.big { height: 12px; background: rgba(255,255,255,.22); }
.bsm-progress span { display: block; height: 100%; border-radius: 99px; background: linear-gradient(90deg, var(--bsm-accent), var(--bsm-primary)); transition: width .25s ease; }
.bsm-empty-state, .bsm-alert, .bsm-lock-box { padding: 28px; grid-column: 1 / -1; }
.bsm-lesson-list { display: grid; gap: 12px; }
.bsm-lesson-list h3 { font-size: 25px; letter-spacing: -0.03em; }
.bsm-lesson-row { display: grid; grid-template-columns: 46px 1fr 36px; gap: 14px; align-items: center; padding: 16px; border: 1px solid var(--bsm-line); border-radius: 18px; background: white; transition: transform .18s ease, box-shadow .18s ease; }
.bsm-lesson-row:hover { transform: translateY(-1px); box-shadow: 0 15px 35px rgba(15,23,42,.08); }
.bsm-lesson-row.is-locked { opacity: .72; }
.bsm-lesson-index { width: 46px; height: 46px; display: grid; place-items: center; border-radius: 15px; background: var(--bsm-bg); font-weight: 900; }
.bsm-lesson-row small { display: block; color: var(--bsm-muted); margin-top: 4px; }
.bsm-back-link { display: inline-flex; margin-bottom: 18px; color: var(--bsm-primary) !important; font-weight: 800; }
.bsm-video-wrap { border-radius: 28px; overflow: hidden; background: #050816; box-shadow: var(--bsm-shadow); }
.bsm-video-player { aspect-ratio: 16 / 9; width: 100%; background: #050816; }
.bsm-video-player iframe { width: 100%; height: 100%; pointer-events: none; }
.bsm-video-controls { display: grid; grid-template-columns: auto auto auto 1fr auto; gap: 10px; align-items: center; padding: 14px; color: white; background: #0b1020; }
.bsm-video-controls button { border: 1px solid rgba(255,255,255,.14); background: rgba(255,255,255,.08); color: white; border-radius: 999px; padding: 10px 14px; font-weight: 800; cursor: pointer; }
.bsm-video-controls input[type="range"] { width: 100%; accent-color: var(--bsm-accent); }
.bsm-progress-label { color: var(--bsm-muted); font-weight: 700; }
.bsm-lesson-content { margin: 28px 0; color: var(--bsm-text); font-size: 17px; line-height: 1.75; }
.bsm-materials, .bsm-quiz { padding: 24px; margin-top: 20px; }
.bsm-material-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 12px; }
.bsm-material { padding: 15px; border-radius: 16px; border: 1px solid var(--bsm-line); background: var(--bsm-bg); font-weight: 800; }
.bsm-quiz fieldset { border: 1px solid var(--bsm-line); border-radius: 18px; padding: 16px; margin: 14px 0; }
.bsm-quiz legend { font-weight: 900; padding: 0 8px; }
.bsm-answer { display: block; margin: 10px 0; color: var(--bsm-muted); }
.bsm-paypal-button { min-height: 44px; }
@media (max-width: 980px) {
  .bsm-auth-grid, .bsm-dashboard-hero, .bsm-course-hero { grid-template-columns: 1fr; }
  .bsm-course-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 680px) {
  .bsm-shell { padding: 18px 12px; }
  .bsm-course-grid { grid-template-columns: 1fr; }
  .bsm-panel, .bsm-dashboard-hero, .bsm-course-hero { padding: 22px; border-radius: 22px; }
  .bsm-video-controls { grid-template-columns: 1fr 1fr 1fr; }
  .bsm-video-controls input[type="range"], .bsm-video-controls span { grid-column: 1 / -1; }
}