/* ── Reset ──────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg:       #ffffff;
  --bg2:      #f5f5f5;
  --bg3:      #ebebeb;
  --border:   #e0e0e0;
  --accent:   #facc15;
  --accent2:  #eab308;
  --black:    #111111;
  --text:     #111111;
  --text2:    #666666;
  --text3:    #aaaaaa;
  --green:    #059669;
  --red:      #dc2626;
  --gold:     #facc15;
  --radius:   10px;
  --radius-lg:16px;
  --shadow:   0 1px 3px rgba(0,0,0,0.06), 0 4px 14px rgba(0,0,0,0.05);
  --shadow-hover: 0 6px 20px rgba(0,0,0,0.1), 0 16px 40px rgba(0,0,0,0.07);
}
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  font-size: 20px;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
button { cursor: pointer; font-family: inherit; border: none; outline: none; }

/* ── Navbar ─────────────────────────────────────────────────── */
.navbar {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.navbar .container {
  display: flex; align-items: center; justify-content: space-between;
  height: 60px; width: 100%; max-width: none; padding: 0 24px;
}
.logo { display: flex; align-items: center; gap: 8px; font-size: 1.05rem; font-weight: 800; color: var(--text); }
.logo-icon { width: 28px; height: 28px; border-radius: 7px; background: var(--accent); display: flex; align-items: center; justify-content: center; font-size: 0.85rem; }
.logo span { color: var(--text); }
.nav-links { display: flex; align-items: center; gap: 2px; }
.nav-link { padding: 6px 14px; border-radius: 7px; color: var(--text2); font-size: 1.05rem; font-weight: 500; transition: all 0.15s; }
.nav-link:hover { color: var(--text); background: var(--bg2); }
.nav-actions { display: flex; align-items: center; gap: 8px; }
.btn-nav-login { padding: 7px 18px; border-radius: 7px; font-size: 1rem; font-weight: 500; color: var(--text2); background: transparent; border: 1px solid var(--border); transition: all 0.15s; }
.btn-nav-login:hover { color: var(--text); border-color: #bbb; }
.btn-nav-reg { padding: 7px 18px; border-radius: 7px; font-size: 1rem; font-weight: 700; color: #fff; background: var(--black); transition: all 0.15s; }
.btn-nav-reg:hover { background: #333; }
.user-menu { display: flex; align-items: center; gap: 10px; }
.user-avatar { width: 34px; height: 34px; border-radius: 50%; background: var(--accent); display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 0.9rem; color: var(--black); }
.user-name { font-size: 1rem; font-weight: 600; }
.btn-logout { padding: 5px 12px; border-radius: 6px; font-size: 0.9rem; color: var(--text2); background: var(--bg3); border: none; transition: all 0.15s; }
.btn-logout:hover { color: var(--red); }

/* ── Layout ─────────────────────────────────────────────────── */
.container { width: 100%; max-width: none; padding: 0 80px; }

/* ── Buttons ────────────────────────────────────────────────── */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; padding: 10px 22px; border-radius: var(--radius); font-size: 0.95rem; font-weight: 600; transition: all 0.15s; cursor: pointer; }
.btn-primary { background: var(--black); color: #fff; border: none; }
.btn-primary:hover { background: #333; transform: translateY(-1px); box-shadow: 0 4px 12px rgba(0,0,0,0.2); }
.btn-outline { background: transparent; color: var(--text); border: 1.5px solid var(--border); }
.btn-outline:hover { border-color: var(--black); background: var(--bg2); }
.btn-lg { padding: 13px 32px; font-size: 1rem; border-radius: 12px; }
.btn-sm { padding: 6px 14px; font-size: 0.83rem; border-radius: 7px; }
.btn-block { width: 100%; }
.btn-green { background: var(--green); color: #fff; border: none; }
.btn-green:hover { background: #047857; transform: translateY(-1px); box-shadow: 0 4px 12px rgba(5,150,105,0.25); }

/* ── Home ───────────────────────────────────────────────────── */
.home-main { padding: 60px 0 80px; }
.home-hero { text-align: center; padding: 80px 0 60px; }
.home-eyebrow {
  display: inline-block; padding: 5px 16px; border-radius: 100px;
  background: var(--accent); color: var(--black);
  font-size: 0.8rem; font-weight: 700; letter-spacing: 0.04em;
  margin-bottom: 22px;
}
.home-hero h1 { font-size: clamp(3rem, 6vw, 5rem); font-weight: 900; line-height: 1.15; color: var(--text); margin-bottom: 18px; }
.gradient-text {
  display: inline-block;
  background: var(--accent);
  color: var(--black);
  -webkit-text-fill-color: var(--black);
  padding: 2px 14px;
  border-radius: 8px;
}
.home-desc { color: var(--text2); font-size: 1.05rem; margin-bottom: 32px; }
.home-card {
  display: flex; align-items: center; justify-content: space-between;
  gap: 28px;
  background: var(--bg); border: 1.5px solid var(--border);
  border-radius: 20px; padding: 32px 36px;
  cursor: pointer; transition: all 0.2s;
  max-width: none;
  box-shadow: var(--shadow);
}
.home-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); border-color: #ccc; }
.home-card-icon { font-size: 2.8rem; text-align: center; }
.home-card-tag { font-size: 0.7rem; font-weight: 700; color: var(--text3); text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 6px; }
.home-card-title { font-size: 1.8rem; font-weight: 800; color: var(--text); margin-bottom: 6px; }
.home-card-sub { color: var(--text2); font-size: 0.88rem; margin-bottom: 12px; }
.home-card-meta { display: flex; gap: 16px; font-size: 0.82rem; color: var(--text3); }
.home-card-action { display: flex; flex-direction: column; align-items: flex-end; gap: 10px; white-space: nowrap; }
.home-price { display: flex; align-items: baseline; gap: 6px; }
.price { font-size: 1.5rem; font-weight: 800; color: var(--text); }
.price-orig { font-size: 0.85rem; color: var(--text3); text-decoration: line-through; }

/* ── Course Card ────────────────────────────────────────────── */
.course-grid { display: grid; grid-template-columns: repeat(auto-fill, 320px); gap: 24px; }
.course-card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg); overflow: hidden; transition: all 0.2s; cursor: pointer; box-shadow: var(--shadow); }
.course-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.course-thumb { height: 220px; background: linear-gradient(135deg, #111 0%, #222 100%); display: flex; align-items: center; justify-content: center; position: relative; }
.course-thumb-icon { font-size: 5rem; filter: drop-shadow(0 2px 8px rgba(0,0,0,0.4)); }
.course-thumb-overlay { display: none; }
.course-badge { position: absolute; top: 12px; right: 12px; padding: 3px 10px; border-radius: 100px; font-size: 0.7rem; font-weight: 700; background: var(--accent); color: var(--black); }
.badge-hot { background: var(--accent); color: var(--black); }
.badge-new { background: var(--accent); color: var(--black); }
.badge-best { background: var(--accent); color: var(--black); }
.course-body { padding: 24px 28px; }
.course-category { font-size: 0.7rem; font-weight: 700; color: var(--text3); text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 7px; }
.course-title { font-size: 1.5rem; font-weight: 800; color: var(--text); margin-bottom: 4px; }
.course-subtitle { font-size: 0.95rem; color: var(--text2); margin-bottom: 12px; }
.course-meta { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 14px; }
.meta-item { font-size: 0.9rem; color: var(--text3); }
.course-footer { display: flex; align-items: center; justify-content: space-between; }
.price-group { display: flex; align-items: baseline; gap: 6px; }
.price-orig { font-size: 0.82rem; color: var(--text3); text-decoration: line-through; }
.discount-tag { padding: 2px 7px; border-radius: 5px; background: var(--accent); color: var(--black); font-size: 0.72rem; font-weight: 700; }
.btn-buy { padding: 10px 22px; border-radius: 8px; font-size: 1rem; font-weight: 700; background: var(--black); color: #fff; transition: all 0.15s; }
.btn-buy:hover { background: #333; }
.btn-unlocked { padding: 10px 22px; border-radius: 8px; font-size: 1rem; font-weight: 600; background: #f0fdf4; color: var(--green); border: 1px solid #bbf7d0; }
.level-badge { padding: 2px 8px; border-radius: 5px; font-size: 0.72rem; font-weight: 700; }
.level-入门 { background: #f0fdf4; color: #16a34a; }
.level-进阶 { background: #fefce8; color: #854d0e; }
.level-高级 { background: var(--accent); color: var(--black); }

/* ── Auth ───────────────────────────────────────────────────── */
.auth-page { min-height: 100vh; display: flex; align-items: center; justify-content: center; background: var(--bg2); padding: 40px 20px; }
.auth-card { width: 100%; max-width: 420px; background: var(--bg); border: 1px solid var(--border); border-radius: 20px; padding: 36px; box-shadow: var(--shadow); }
.auth-logo { text-align: center; margin-bottom: 28px; }
.auth-title { font-size: 1.5rem; font-weight: 800; text-align: center; margin-bottom: 4px; color: var(--text); }
.auth-sub { text-align: center; color: var(--text2); font-size: 0.88rem; margin-bottom: 28px; }
.form-group { margin-bottom: 16px; }
.form-label { display: block; font-size: 0.83rem; font-weight: 600; color: var(--text2); margin-bottom: 7px; }
.form-input { width: 100%; padding: 10px 14px; background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); color: var(--text); font-size: 0.93rem; font-family: inherit; transition: all 0.15s; outline: none; }
.form-input:focus { border-color: var(--black); background: #fff; box-shadow: 0 0 0 3px rgba(0,0,0,0.06); }
.form-input::placeholder { color: var(--text3); }
.form-error { font-size: 0.78rem; color: var(--red); margin-top: 4px; }
.auth-divider { display: flex; align-items: center; gap: 12px; margin: 20px 0; }
.auth-divider span { color: var(--text3); font-size: 0.78rem; white-space: nowrap; }
.auth-divider::before, .auth-divider::after { content: ''; flex: 1; height: 1px; background: var(--border); }
.auth-switch { text-align: center; margin-top: 20px; font-size: 0.88rem; color: var(--text2); }
.auth-switch a { color: var(--text); font-weight: 700; text-decoration: underline; text-decoration-color: var(--accent); text-underline-offset: 3px; }
.alert { padding: 10px 14px; border-radius: 8px; font-size: 0.88rem; margin-bottom: 16px; display: none; }
.alert-error { background: #fef2f2; border: 1px solid #fecaca; color: var(--red); }
.alert-success { background: #f0fdf4; border: 1px solid #bbf7d0; color: var(--green); }

/* ── Dashboard ──────────────────────────────────────────────── */
.dash-layout { display: grid; grid-template-columns: 220px 1fr; gap: 24px; padding: 32px 0; min-height: calc(100vh - 60px - 65px); }
.dash-sidebar { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 18px; height: fit-content; position: sticky; top: 76px; box-shadow: var(--shadow); }
.dash-user { text-align: center; padding: 16px 0 14px; border-bottom: 1px solid var(--border); margin-bottom: 12px; }
.dash-avatar { width: 52px; height: 52px; border-radius: 50%; background: var(--accent); display: flex; align-items: center; justify-content: center; font-size: 1.3rem; font-weight: 800; color: var(--black); margin: 0 auto 10px; }
.dash-username { font-weight: 700; font-size: 0.95rem; }
.dash-email { color: var(--text3); font-size: 0.78rem; margin-top: 2px; }
.dash-nav-item { display: flex; align-items: center; gap: 9px; padding: 10px 14px; border-radius: 8px; margin-bottom: 2px; color: var(--text2); font-size: 1rem; font-weight: 500; cursor: pointer; transition: all 0.15s; }
.dash-nav-item:hover { background: var(--bg2); color: var(--text); }
.dash-nav-item.active { background: var(--accent); color: var(--black); font-weight: 700; }
.dash-content { min-width: 0; }
.dash-panel { display: none; }
.dash-panel.active { display: block; }
.dash-header { margin-bottom: 20px; }
.dash-header h2 { font-size: 1.6rem; font-weight: 800; }
.dash-header p { color: var(--text2); font-size: 1rem; margin-top: 3px; }
.my-courses-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(380px, 1fr)); gap: 28px; }
.my-course-card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg); overflow: hidden; transition: all 0.2s; box-shadow: var(--shadow); cursor: pointer; }
.my-course-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); }
.my-course-thumb { height: 200px; background: linear-gradient(135deg, #111, #222); display: flex; align-items: center; justify-content: center; font-size: 4.5rem; }
.my-course-body { padding: 24px; }
.my-course-title { font-weight: 800; font-size: 1.3rem; margin-bottom: 8px; }
.my-course-meta { font-size: 1rem; color: var(--text3); margin-bottom: 14px; }
.btn-learn { width: 100%; padding: 12px; border-radius: 10px; font-size: 1rem; font-weight: 700; background: var(--black); color: #fff; transition: all 0.15s; }
.btn-learn:hover { background: #333; }
.empty-state { text-align: center; padding: 50px 20px; color: var(--text3); }
.empty-state-icon { font-size: 2.5rem; margin-bottom: 12px; }
.empty-state p { font-size: 0.9rem; margin-bottom: 14px; }

/* ── Course Detail ──────────────────────────────────────────── */
.course-detail-hero { background: var(--bg2); border-bottom: 1px solid var(--border); padding: 48px 0; }
.course-detail-layout { display: grid; grid-template-columns: 1fr 340px; gap: 40px; align-items: stretch; min-height: 100%; }
.course-detail-meta { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.course-detail-title { font-size: clamp(2rem, 4vw, 3rem); font-weight: 900; margin-bottom: 12px; }
.course-detail-sub { font-size: 1.2rem; color: var(--text2); margin-bottom: 20px; }
.course-detail-stats { display: flex; gap: 18px; flex-wrap: wrap; margin-top: 20px; }
.detail-stat { display: flex; align-items: center; gap: 5px; font-size: 0.87rem; color: var(--text2); }
.buy-card { background: var(--bg); border: 1.5px solid var(--border); border-radius: var(--radius-lg); padding: 24px; position: sticky; top: 76px; box-shadow: var(--shadow); }
.buy-price-big { font-size: 2.2rem; font-weight: 900; color: var(--text); }
.buy-price-orig { font-size: 0.95rem; color: var(--text3); text-decoration: line-through; margin-left: 6px; }
.buy-discount { display: inline-block; padding: 3px 10px; border-radius: 6px; margin-top: 4px; background: var(--accent); color: var(--black); font-size: 0.78rem; font-weight: 700; }
.buy-features { margin: 16px 0; }
.buy-feature-item { display: flex; align-items: center; gap: 8px; padding: 9px 0; border-bottom: 1px solid var(--border); font-size: 1rem; color: var(--text2); }
.buy-feature-item:last-child { border: none; }
.buy-feature-icon { color: var(--green); }
.course-tabs { display: flex; border-bottom: 1.5px solid var(--border); margin-bottom: 28px; }
.course-tab { padding: 12px 20px; font-size: 0.9rem; font-weight: 600; color: var(--text3); cursor: pointer; border-bottom: 2.5px solid transparent; margin-bottom: -1.5px; transition: all 0.15s; }
.course-tab.active { color: var(--text); border-bottom-color: var(--text); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }
.lesson-item { display: flex; align-items: center; justify-content: space-between; padding: 12px 14px; border-radius: 8px; margin-bottom: 4px; background: var(--bg2); transition: all 0.15s; }
.lesson-item:hover { background: var(--bg3); }
.lesson-item-left { display: flex; align-items: center; gap: 10px; }
.lesson-num { width: 26px; height: 26px; border-radius: 50%; background: var(--accent); color: var(--black); font-size: 0.75rem; font-weight: 700; display: flex; align-items: center; justify-content: center; }
.lesson-title { font-size: 0.88rem; font-weight: 500; }
.lesson-duration { font-size: 0.78rem; color: var(--text3); }
.free-badge { padding: 2px 7px; border-radius: 4px; background: var(--accent); color: var(--black); font-size: 0.7rem; font-weight: 700; }

/* ── Pay ────────────────────────────────────────────────────── */
.pay-page { padding: 48px 0; min-height: calc(100vh - 60px - 65px); }
.pay-card { max-width: 520px; margin: 0 auto; background: var(--bg); border: 1px solid var(--border); border-radius: 20px; overflow: hidden; box-shadow: var(--shadow); }
.pay-header { padding: 24px 28px; border-bottom: 1px solid var(--border); }
.pay-header h2 { font-size: 1.2rem; font-weight: 800; }
.pay-header p { color: var(--text2); font-size: 0.82rem; margin-top: 3px; }
.pay-body { padding: 28px; }
.pay-course-info { display: flex; align-items: center; gap: 14px; padding: 14px; background: var(--bg2); border-radius: 10px; margin-bottom: 22px; }
.pay-course-icon { width: 46px; height: 46px; border-radius: 10px; background: #111; display: flex; align-items: center; justify-content: center; font-size: 1.2rem; flex-shrink: 0; }
.pay-course-title { font-weight: 700; font-size: 0.92rem; }
.pay-course-sub { font-size: 0.78rem; color: var(--text3); margin-top: 2px; }
.pay-amount-section { margin-bottom: 24px; }
.pay-amount-label { font-size: 0.82rem; color: var(--text2); margin-bottom: 5px; }
.pay-amount-big { font-size: 2.4rem; font-weight: 900; color: var(--text); }
.pay-amount-sub { font-size: 0.78rem; color: var(--text3); margin-top: 3px; }
.pay-methods { margin-bottom: 24px; }
.pay-methods-label { font-size: 0.82rem; font-weight: 600; color: var(--text2); margin-bottom: 10px; }
.pay-method-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.pay-method-btn { padding: 12px; border-radius: 8px; border: 1.5px solid var(--border); background: var(--bg2); cursor: pointer; transition: all 0.15s; display: flex; flex-direction: column; align-items: center; gap: 5px; font-size: 0.82rem; font-weight: 600; color: var(--text2); }
.pay-method-btn:hover { border-color: var(--black); }
.pay-method-btn.selected { border-color: var(--black); background: var(--bg3); color: var(--text); }
.pay-method-icon { font-size: 1.4rem; }
.pay-notice { font-size: 0.78rem; color: var(--text3); padding: 10px 14px; background: var(--bg2); border-radius: 8px; margin-bottom: 20px; line-height: 1.7; }
.pay-footer { padding: 16px 28px; background: var(--bg2); border-top: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; }
.pay-security { display: flex; align-items: center; gap: 5px; font-size: 0.78rem; color: var(--text3); }
.pay-success-overlay { position: fixed; inset: 0; z-index: 200; background: rgba(0,0,0,0.5); backdrop-filter: blur(6px); display: none; align-items: center; justify-content: center; }
.pay-success-card { background: var(--bg); border-radius: 20px; padding: 44px 36px; text-align: center; max-width: 360px; width: 90%; box-shadow: 0 20px 60px rgba(0,0,0,0.15); animation: popIn 0.35s cubic-bezier(0.34,1.56,0.64,1); }
@keyframes popIn { from { transform: scale(0.85); opacity: 0; } to { transform: scale(1); opacity: 1; } }
.success-icon { font-size: 3rem; margin-bottom: 14px; }
.success-title { font-size: 1.3rem; font-weight: 800; margin-bottom: 6px; }
.success-sub { color: var(--text2); font-size: 0.88rem; margin-bottom: 24px; }

/* ── Toast ──────────────────────────────────────────────────── */
.toast-container { position: fixed; top: 72px; right: 20px; z-index: 300; display: flex; flex-direction: column; gap: 8px; }
.toast { padding: 10px 16px; border-radius: 8px; font-size: 0.87rem; font-weight: 500; box-shadow: var(--shadow-hover); animation: slideIn 0.25s ease; max-width: 300px; }
@keyframes slideIn { from { transform: translateX(110%); opacity: 0; } to { transform: translateX(0); opacity: 1; } }
.toast-success { background: #fff; border: 1px solid #bbf7d0; color: var(--green); }
.toast-error { background: #fff; border: 1px solid #fecaca; color: var(--red); }
.toast-info { background: #fff; border: 1px solid var(--border); color: var(--text); }

/* ── Spinner ────────────────────────────────────────────────── */
.spinner { display: inline-block; width: 18px; height: 18px; border: 2px solid var(--border); border-top-color: var(--black); border-radius: 50%; animation: spin 0.7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Section ────────────────────────────────────────────────── */
.section { padding: 64px 0; }
.section-header { text-align: center; margin-bottom: 40px; }
.section-header h2 { font-size: 1.8rem; font-weight: 800; }
.section-header p { color: var(--text2); margin-top: 8px; }
.section-tag { display: inline-block; padding: 4px 14px; border-radius: 100px; background: var(--accent); color: var(--black); font-size: 0.75rem; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase; margin-bottom: 12px; }

/* ── Footer ─────────────────────────────────────────────────── */
footer { border-top: 1px solid var(--border); padding: 28px 0; background: var(--bg); }
.footer-inner { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 12px; width: 100%; max-width: none; padding: 0 24px; }
.footer-copy { color: var(--text3); font-size: 0.82rem; }
.footer-links { display: flex; gap: 18px; }
.footer-links a { color: var(--text3); font-size: 0.82rem; transition: color 0.15s; }
.footer-links a:hover { color: var(--text); }

/* ── Tags ───────────────────────────────────────────────────── */
.tag { padding: 3px 9px; border-radius: 5px; font-size: 0.73rem; font-weight: 500; background: var(--bg3); color: var(--text2); border: 1px solid var(--border); }
.tag-row { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 10px; }

/* ── Admin ──────────────────────────────────────────────────── */
.admin-wrap { max-width: 720px; margin: 48px auto; padding: 0 24px; }
.lesson-row { display: flex; align-items: center; gap: 12px; padding: 12px 16px; background: var(--bg); border: 1px solid var(--border); border-radius: 10px; margin-bottom: 6px; box-shadow: var(--shadow); transition: all 0.15s; }
.lesson-row:hover { border-color: #bbb; }
.lesson-num { width: 26px; height: 26px; border-radius: 50%; background: var(--accent); color: var(--black); font-size: 0.75rem; font-weight: 700; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.lesson-title { flex: 1; font-size: 0.88rem; font-weight: 500; }
.lesson-file { font-size: 0.78rem; color: var(--text3); }
.lesson-file a { color: var(--green); }
.upload-label { padding: 5px 12px; border-radius: 6px; font-size: 0.8rem; font-weight: 600; background: var(--bg3); color: var(--text); border: 1px solid var(--border); cursor: pointer; white-space: nowrap; transition: all 0.15s; }
.upload-label:hover { background: var(--bg2); border-color: #bbb; }
.del-btn { padding: 5px 10px; border-radius: 6px; font-size: 0.78rem; background: #fef2f2; color: var(--red); border: 1px solid #fecaca; cursor: pointer; transition: all 0.15s; }
.del-btn:hover { background: #fee2e2; }
input[type=file] { display: none; }

/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 860px) {
  .dash-layout { grid-template-columns: 1fr; }
  .dash-sidebar { position: static; }
  .course-detail-layout { grid-template-columns: 1fr; }
  .buy-card { position: static; }
  .home-card { grid-template-columns: 1fr; text-align: center; padding: 24px; }
  .home-card-action { align-items: center; }
  .home-card-meta { justify-content: center; }
}
@media (max-width: 580px) {
  .nav-links { display: none; }
  .course-grid { grid-template-columns: 1fr; }
  .pay-method-grid { grid-template-columns: 1fr; }
}