@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,400;1,600&family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=Inter:wght@400;500;600;700;800&display=swap');

/* =====================================================
   DESIGN TOKENS
   ===================================================== */
:root {
    --primary:        #7a1318;
    --primary-dark:   #54090c;
    --primary-light:  #fdf4f4;
    --primary-glow:   rgba(122, 19, 24, 0.18);
    --accent:         #d97706;
    --success:        #15803d;
    --info:           #1d4ed8;

    --bg:             #f4f6f9;
    --bg-white:       #ffffff;
    --surface:        #ffffff;
    --border:         #e5e7eb;
    --border-light:   #f0f2f5;

    --text-1:         #0f172a;
    --text-2:         #334155;
    --text-3:         #64748b;
    --text-4:         #94a3b8;

    --font:           'Be Vietnam Pro', 'Plus Jakarta Sans', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --radius-sm:      3px;
    --radius:         6px;
    --radius-lg:      10px;
    --radius-xl:      14px;
    --radius-2xl:     20px;
    --radius-full:    9999px;

    --shadow-sm:      0 1px 4px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
    --shadow:         0 4px 20px rgba(0,0,0,.08), 0 1px 4px rgba(0,0,0,.04);
    --shadow-lg:      0 12px 40px rgba(0,0,0,.12), 0 4px 12px rgba(0,0,0,.06);
    --shadow-xl:      0 24px 60px rgba(0,0,0,.16), 0 8px 20px rgba(0,0,0,.08);
    --shadow-primary: 0 6px 24px rgba(193, 32, 38, 0.35);
    --shadow-primary-sm: 0 3px 12px rgba(193, 32, 38, 0.25);

    --transition:     .22s cubic-bezier(.4,0,.2,1);
    --transition-slow: .4s cubic-bezier(.4,0,.2,1);
    --header-h:       70px;
}

/* =====================================================
   KEYFRAME ANIMATIONS
   ===================================================== */
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(20px); }
    to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
    from { opacity: 0; }
    to   { opacity: 1; }
}
@keyframes scaleIn {
    from { opacity: 0; transform: scale(.94); }
    to   { opacity: 1; transform: scale(1); }
}
@keyframes shimmer {
    0%   { background-position: -200% center; }
    100% { background-position: 200% center; }
}
@keyframes pulse-ring {
    0%   { box-shadow: 0 0 0 0 rgba(193,32,38,.4); }
    70%  { box-shadow: 0 0 0 10px rgba(193,32,38,0); }
    100% { box-shadow: 0 0 0 0 rgba(193,32,38,0); }
}
@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50%       { transform: translateY(-8px); }
}
@keyframes toastIn {
    from { opacity: 0; transform: translateX(30px); }
    to   { opacity: 1; transform: translateX(0); }
}

/* =====================================================
   RESET & BASE
   ===================================================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text-1);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

main { flex: 1; }

a { text-decoration: none; color: inherit; transition: color var(--transition); }
a:hover { color: var(--primary); }

ul { list-style: none; }
img { display: block; max-width: 100%; }

/* =====================================================
   LAYOUT
   ===================================================== */
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 24px; box-sizing: border-box; }
main .container,
body > .container {
    width: 100% !important;
    max-width: 1250px !important;
    padding: 0 5px !important;
    box-sizing: border-box;
}
.container-wide  { max-width: 1400px; margin: 0 auto; padding: 0 24px; }
.container-fluid { width: 100%; padding: 0 24px; }

/* =====================================================
   TYPOGRAPHY
   ===================================================== */
.text-xs   { font-size: 12px; }
.text-sm   { font-size: 13px; }
.text-base { font-size: 15px; }
.text-lg   { font-size: 18px; }
.text-xl   { font-size: 22px; }
.text-2xl  { font-size: 28px; }
.text-3xl  { font-size: 36px; }
.text-4xl  { font-size: 48px; }

.font-medium    { font-weight: 500; }
.font-semibold  { font-weight: 600; }
.font-bold      { font-weight: 700; }
.font-extrabold { font-weight: 800; }

.text-muted   { color: var(--text-3); }
.text-primary { color: var(--primary); }
.text-center  { text-align: center; }

.section-title {
    font-size: 30px;
    font-weight: 800;
    color: var(--text-1);
    margin-bottom: 8px;
    letter-spacing: -.6px;
    line-height: 1.2;
}
.section-subtitle {
    font-size: 16px;
    color: var(--text-3);
    margin-bottom: 40px;
    line-height: 1.6;
}

/* Gradient text utility */
.text-gradient {
    background: linear-gradient(135deg, var(--primary), #ff6b6b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* =====================================================
   BUTTONS
   ===================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 11px 22px;
    border-radius: var(--radius);
    font-family: var(--font);
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    border: none;
    transition: all var(--transition);
    white-space: nowrap;
    position: relative;
    overflow: hidden;
    letter-spacing: .01em;
}
.btn::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(255,255,255,0);
    transition: background var(--transition);
}
.btn:hover::after { background: rgba(255,255,255,.08); }

.btn-sm  { padding: 7px 14px; font-size: 13px; }
.btn-lg  { padding: 14px 30px; font-size: 15px; }
.btn-block { width: 100%; }

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff;
    box-shadow: var(--shadow-primary-sm);
}
.btn-primary:hover {
    background: linear-gradient(135deg, #d42c33, var(--primary));
    color: #fff;
    transform: translateY(-2px);
    box-shadow: var(--shadow-primary);
}
.btn-primary:active { transform: translateY(0); box-shadow: var(--shadow-primary-sm); }

.btn-secondary {
    background: var(--bg-white);
    color: var(--text-1);
    border: 1.5px solid var(--border);
}
.btn-secondary:hover { background: var(--bg); border-color: var(--text-4); transform: translateY(-1px); box-shadow: var(--shadow-sm); }

.btn-ghost {
    background: transparent;
    color: var(--text-2);
    border: none;
}
.btn-ghost:hover { background: var(--bg); color: var(--text-1); }

.btn-outline-primary {
    background: transparent;
    color: var(--primary);
    border: 1.5px solid var(--primary);
}
.btn-outline-primary:hover {
    background: var(--primary);
    color: #fff;
    box-shadow: var(--shadow-primary-sm);
    transform: translateY(-1px);
}

/* Loading state */
.btn.loading {
    pointer-events: none;
    opacity: .75;
}
.btn.loading::before {
    content: '';
    width: 14px;
    height: 14px;
    border: 2px solid rgba(255,255,255,.4);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin .7s linear infinite;
    flex-shrink: 0;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* =====================================================
   BADGE / CHIP
   ===================================================== */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 3px 10px;
    border-radius: var(--radius-sm);
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: .5px;
}
.badge-primary { background: var(--primary-light); color: var(--primary); }
.badge-success { background: #d1fae5; color: #059669; }
.badge-accent  { background: #fef3c7; color: #d97706; }
.badge-info    { background: #dbeafe; color: #2563eb; }
.badge-new     { background: var(--primary); color: #fff; }

/* =====================================================
   FORM CONTROLS
   ===================================================== */
.form-group { margin-bottom: 20px; }

.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-2);
    margin-bottom: 7px;
    letter-spacing: .01em;
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    font-family: var(--font);
    font-size: 14px;
    background: var(--bg-white);
    color: var(--text-1);
    outline: none;
    transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}
.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(193,32,38,.1);
    background: #fff;
}
.form-control::placeholder { color: var(--text-4); }

textarea.form-control { resize: vertical; min-height: 100px; }

/* =====================================================
   CARDS
   ===================================================== */
.card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(193,32,38,.15);
}

/* =====================================================
   STARS / RATING
   ===================================================== */
.stars { color: #f59e0b; font-size: 13px; letter-spacing: 1px; }
.rating { display: flex; align-items: center; gap: 6px; font-size: 13px; }
.rating-score { font-weight: 700; color: var(--text-1); }
.rating-count { color: var(--text-3); }

/* =====================================================
   HEADER
   ===================================================== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 500;
    background: rgba(255,255,255,.94);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(0,0,0,.06);
    height: var(--header-h);
    transition: background var(--transition-slow), box-shadow var(--transition-slow);
}
.site-header.scrolled {
    background: rgba(255,255,255,.98);
    box-shadow: 0 6px 24px rgba(0,0,0,.06);
    border-bottom-color: transparent;
}
.site-header .container {
    height: 100%;
    max-width: 1250px !important;
    margin: 0 auto;
    padding: 0 24px !important;
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
}

.header-logo {
    margin-right: auto;
}

.header-actions {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 16px;
}

.btn-my-courses:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(122, 19, 24, 0.38) !important;
    background: linear-gradient(135deg, #8c171d 0%, #54090c 100%) !important;
}
.lang-selector:hover {
    background: rgba(122, 19, 24, 0.08) !important;
    border-color: rgba(122, 19, 24, 0.2) !important;
    color: #7a1318 !important;
}
.user-avatar-btn:hover {
    transform: scale(1.06);
    box-shadow: 0 4px 16px rgba(122, 19, 24, 0.35) !important;
}

.header-logo {
    display: flex;
    align-items: center;
    font-size: 22px;
    font-weight: 900;
    color: var(--primary);
    letter-spacing: -1px;
    flex-shrink: 0;
    transition: opacity var(--transition);
}
.header-logo:hover { opacity: .85; color: var(--primary); }
.header-logo span { color: var(--text-1); }

.header-search {
    flex: 1;
    max-width: 480px;
    position: relative;
}
.header-search input {
    width: 100%;
    padding: 9px 16px 9px 40px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius-full);
    font-family: var(--font);
    font-size: 14px;
    background: var(--bg);
    outline: none;
    transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}
.header-search input:focus {
    border-color: var(--primary);
    background: #fff;
    box-shadow: 0 0 0 3px rgba(193,32,38,.08);
}
.header-search .search-icon {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-3);
    font-size: 16px;
    pointer-events: none;
}

.header-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    flex: 1;
}
.header-nav a {
    padding: 7px 13px;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 500;
    color: var(--text-2);
    transition: all var(--transition);
    position: relative;
    white-space: nowrap;
}
.header-nav a::after {
    content: '';
    position: absolute;
    bottom: 3px;
    left: 50%;
    right: 50%;
    height: 2px;
    background: var(--primary);
    border-radius: var(--radius-full);
    transition: left var(--transition), right var(--transition);
    opacity: 0;
}
.header-nav a:hover { color: var(--primary); background: var(--primary-light); }
.header-nav a.active {
    color: var(--primary);
    background: var(--primary-light);
    font-weight: 600;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-shrink: 0;
}

.cart-btn {
    position: relative;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg);
    border: 1.5px solid var(--border);
    color: var(--text-2);
    cursor: pointer;
    transition: all var(--transition);
    font-size: 18px;
    text-decoration: none;
}
.cart-btn:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-light); transform: translateY(-1px); }
.noti-btn:hover { border-color: var(--primary) !important; color: var(--primary) !important; background: var(--primary-light) !important; transform: translateY(-1px) !important; }
.cart-badge {
    position: absolute;
    top: -5px;
    right: -5px;
    background: var(--primary);
    color: #fff;
    font-size: 10px;
    font-weight: 700;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid var(--bg-white);
    animation: pulse-ring 2s ease-in-out infinite;
}

.user-menu { position: relative; }
.user-avatar-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), #e83e3e);
    color: #fff;
    font-weight: 800;
    font-size: 14px;
    border: 2px solid rgba(193,32,38,.2);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    letter-spacing: .02em;
}
.user-avatar-btn:hover {
    transform: scale(1.08);
    box-shadow: 0 0 0 3px rgba(193,32,38,.25), var(--shadow-primary-sm);
}

.user-dropdown {
    position: absolute;
    right: 0;
    top: calc(100% + 12px);
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    width: 228px;
    padding: 8px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px) scale(.97);
    transition: all var(--transition);
    z-index: 600;
}
.user-menu:hover .user-dropdown,
.user-menu.open .user-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
}
.user-dropdown a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: var(--radius);
    font-size: 14px;
    color: var(--text-2);
    transition: all var(--transition);
}
.user-dropdown a:hover { background: var(--bg); color: var(--primary); }
.user-dropdown hr { border: none; border-top: 1px solid var(--border-light); margin: 6px 0; }
.user-info { padding: 12px 12px 8px; }
.user-info .name  { font-weight: 700; font-size: 14px; color: var(--text-1); }
.user-info .email { font-size: 12px; color: var(--text-3); margin-top: 2px; }

/* =====================================================
   FOOTER
   ===================================================== */
.site-footer {
    background: #0f172a;
    color: #94a3b8;
    padding-top: 64px;
    margin-top: auto;
}
.footer-grid {
    display: grid;
    grid-template-columns: 1.8fr 1fr 1.1fr 1.5fr;
    gap: 36px;
    padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,.08);
}
.footer-col-title {
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: #e2e8f0;
    margin-bottom: 20px;
}
.footer-logo {
    font-size: 26px;
    font-weight: 900;
    color: #fff;
    letter-spacing: -1px;
    margin-bottom: 12px;
}
.footer-logo span { color: var(--primary); }
.footer-desc { font-size: 14px; line-height: 1.75; color: #64748b; margin-bottom: 20px; }
.footer-links { display: flex; flex-direction: column; gap: 10px; }
.footer-links a {
    font-size: 14px;
    color: #64748b;
    transition: color var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.footer-links a:hover { color: #e2e8f0; }
.footer-bottom {
    padding: 20px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
    color: #475569;
}
.footer-bottom a { color: #475569; }
.footer-bottom a:hover { color: #e2e8f0; }

.footer-social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: rgba(255,255,255,.06);
    border: 1px solid rgba(255,255,255,.12);
    border-radius: 50%;
    color: #94a3b8;
    transition: all var(--transition);
}
.footer-social-link:hover {
    background: var(--primary);
    color: #ffffff;
    border-color: var(--primary);
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(122, 19, 24, 0.4);
}

/* SVG icon utility */
.search-icon { display: block; }
.icon-svg { display: inline-block; vertical-align: middle; }

/* =====================================================
   TOAST NOTIFICATION
   ===================================================== */
.toast-container {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.toast {
    background: #1e293b;
    color: #f1f5f9;
    padding: 14px 20px;
    border-radius: var(--radius-lg);
    font-size: 14px;
    font-weight: 500;
    box-shadow: var(--shadow-xl);
    display: flex;
    align-items: center;
    gap: 12px;
    min-width: 300px;
    max-width: 380px;
    animation: toastIn .3s cubic-bezier(.34,1.56,.64,1);
    border-left: 4px solid var(--success);
}
.toast.error { border-left-color: var(--primary); }
.toast.info  { border-left-color: var(--info); }
.toast.warn  { border-left-color: var(--accent); }

/* =====================================================
   HERO BANNER (shared)
   ===================================================== */
.hero-banner {
    background: linear-gradient(135deg, #1e0304 0%, #7a1318 40%, #c12026 100%);
    border-radius: var(--radius-xl);
    padding: 60px;
    color: #fff;
    position: relative;
    overflow: hidden;
}
.hero-banner::before {
    content: 'PTIT';
    position: absolute;
    right: -20px;
    bottom: -30px;
    font-size: 160px;
    font-weight: 900;
    color: rgba(255,255,255,.04);
    line-height: 1;
    pointer-events: none;
}
.hero-title { font-size: 40px; font-weight: 800; margin-bottom: 16px; line-height: 1.2; }
.hero-desc  { font-size: 16px; opacity: .85; max-width: 560px; margin-bottom: 28px; }

/* =====================================================
   COURSE CARDS
   ===================================================== */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
}
.course-card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.course-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(193,32,38,.18);
}

.card-thumb {
    aspect-ratio: 16/9;
    background: linear-gradient(135deg, #1e0304, #c12026);
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    color: rgba(255,255,255,.12);
    font-size: 80px;
    font-weight: 900;
    letter-spacing: -3px;
}
.card-thumb::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(0,0,0,.25) 0%, transparent 50%);
}
.card-thumb img { width: 100%; height: 100%; object-fit: cover; position: absolute; inset: 0; }
.card-body { padding: 20px; display: flex; flex-direction: column; flex: 1; }
.card-title {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-1);
    margin-bottom: 8px;
    line-height: 1.4;
}
.card-instructor { font-size: 12px; color: var(--text-3); margin-bottom: 8px; }
.card-meta { font-size: 12px; color: var(--text-3); margin-bottom: 10px; }

/* =====================================================
   SESSION / CHAPTER CARDS
   ===================================================== */
.session-card {
    background: var(--bg-white);
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    padding: 14px 16px;
    margin-bottom: 10px;
    cursor: pointer;
    transition: all var(--transition);
}
.session-card:hover, .session-card.active {
    border-color: var(--primary);
    background: var(--primary-light);
    transform: translateX(3px);
}
.session-title { font-weight: 600; font-size: 14px; color: var(--text-1); margin-bottom: 4px; }
.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 11px;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--success);
    color: var(--success);
}
.status-badge.pending { border-color: var(--accent); color: var(--accent); }
.status-badge.locked  { border-color: var(--text-3); color: var(--text-3); }

/* =====================================================
   PROGRESS BAR
   ===================================================== */
.progress-bar-wrap {
    background: var(--border-light);
    border-radius: var(--radius-full);
    height: 7px;
    overflow: hidden;
}
.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), #e83e3e);
    border-radius: var(--radius-full);
    transition: width .6s cubic-bezier(.4,0,.2,1);
    position: relative;
}
.progress-bar-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,.35) 50%, transparent 100%);
    background-size: 200% auto;
    animation: shimmer 2.5s linear infinite;
}

/* =====================================================
   SECTION WRAPPER
   ===================================================== */
.section    { padding: 80px 0; }
.section-sm { padding: 48px 0; }
.section-header { text-align: center; margin-bottom: 48px; }

/* =====================================================
   SKELETON LOADING
   ===================================================== */
.skeleton {
    background: linear-gradient(90deg, var(--border-light) 25%, #e9ecef 50%, var(--border-light) 75%);
    background-size: 200% auto;
    animation: shimmer 1.5s linear infinite;
    border-radius: var(--radius);
}

/* =====================================================
   RESPONSIVE
   ===================================================== */
@media (max-width: 1024px) {
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .header-search { max-width: 300px; }
}
@media (max-width: 768px) {
    .site-header .container { gap: 12px; }
    .header-search { display: none; }
    .header-nav { display: none; }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
    .section { padding: 48px 0; }
    .hero-title { font-size: 28px; }
    .hero-banner { padding: 36px 24px; }
    .course-grid { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
    .footer-grid { grid-template-columns: 1fr; }
    .footer-bottom { flex-direction: column; gap: 10px; text-align: center; }
}

/* =====================================================
   SYSTEM TOAST NOTIFICATION SYSTEM
   ===================================================== */
.system-toast-container {
    position: fixed;
    top: 24px;
    right: 24px;
    z-index: 100000;
    display: flex;
    flex-direction: column;
    gap: 12px;
    pointer-events: none;
}
.system-toast {
    pointer-events: auto;
    min-width: 320px;
    max-width: 440px;
    padding: 14px 20px;
    border-radius: var(--radius-lg, 10px);
    background: #ffffff;
    box-shadow: 0 16px 36px rgba(15, 23, 42, 0.18), 0 4px 12px rgba(0, 0, 0, 0.08);
    display: flex;
    align-items: center;
    gap: 14px;
    font-size: 14px;
    font-weight: 600;
    line-height: 1.45;
    color: #0f172a;
    border: 1px solid #e2e8f0;
    border-left: 5px solid #7a1318;
    animation: toastIn 0.35s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
    transition: all 0.3s ease;
}
.system-toast.toast-success {
    border-left-color: #10b981;
    background: #f0fdf4;
    color: #065f46;
}
.system-toast.toast-error {
    border-left-color: #ef4444;
    background: #fef2f2;
    color: #991b1b;
}
.system-toast.toast-warning {
    border-left-color: #f59e0b;
    background: #fffbeb;
    color: #92400e;
}
.system-toast.toast-info {
    border-left-color: #3b82f6;
    background: #eff6ff;
    color: #1e40af;
}
.system-toast-icon {
    font-size: 18px;
    line-height: 1;
    flex-shrink: 0;
    display: flex;
    align-items: center;
}
.system-toast-msg {
    flex: 1;
}
.system-toast-close {
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
    color: currentColor;
    opacity: 0.6;
    padding: 0 2px;
    line-height: 1;
}
.system-toast-close:hover { opacity: 1; }