:root {
    --primary: #1a2a6c;
    --primary-dark: #111d4a;
    --primary-light: #2a3d8f;
    --accent: #c5a44e;
    --accent-dark: #a8893a;
    --accent-light: #d4b96a;
    --secondary: #64748b;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
    --dark: #0f1629;
    --light: #f8f9fc;
    --white: #ffffff;
    --gray-100: #f1f3f8;
    --gray-200: #e2e5ef;
    --gray-300: #c8cdd9;
    --gray-400: #94a0b8;
    --gray-500: #64708b;
    --gray-600: #475169;
    --gray-700: #2d3550;
    --gray-800: #1a2140;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius: 8px;
    --radius-lg: 12px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--gray-800);
    background: var(--gray-100);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.navbar {
    background: var(--primary);
    box-shadow: 0 2px 8px rgba(26, 42, 108, 0.3);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.625rem;
}

.nav-logo {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    object-fit: cover;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--accent);
}

.main-content {
    min-height: calc(100vh - 128px);
}

.hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 5rem 1.5rem;
    text-align: center;
}

.hero-content {
    max-width: 700px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 2.75rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero p {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 0.9375rem;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--accent);
    color: var(--primary-dark);
}

.btn-primary:hover {
    background: var(--accent-dark);
}

.btn-outline {
    background: transparent;
    border: 2px solid rgba(255, 255, 255, 0.4);
    color: var(--white);
}

.btn-outline:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.btn-secondary {
    background: var(--gray-200);
    color: var(--gray-600);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1rem;
}

.btn-full {
    width: 100%;
}

.section {
    padding: 4rem 0;
}

.section-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: 2rem;
    text-align: center;
}

.page-header {
    background: var(--primary);
    padding: 3rem 1.5rem;
    text-align: center;
    border-bottom: 3px solid var(--accent);
}

.page-header h1 {
    font-size: 2rem;
    color: var(--white);
    margin-bottom: 0.5rem;
}

.page-header p {
    color: rgba(255, 255, 255, 0.7);
}

.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
}

.course-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    border-top: 3px solid var(--accent);
}

.course-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.course-image {
    height: 180px;
    background: var(--gray-100);
    overflow: hidden;
    position: relative;
}

.course-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.course-placeholder {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-light);
    background: linear-gradient(135deg, var(--gray-100) 0%, var(--gray-200) 100%);
}

.course-placeholder.large {
    height: 300px;
}

.course-content {
    padding: 1.5rem;
}

.course-type {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--primary);
    background: rgba(26, 42, 108, 0.08);
    padding: 0.25rem 0.75rem;
    border-radius: 100px;
    margin-bottom: 0.75rem;
}

.course-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 0.5rem;
}

.course-content p {
    color: var(--gray-500);
    font-size: 0.9375rem;
    margin-bottom: 1rem;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--gray-200);
    margin-bottom: 1rem;
}

.course-meta span {
    font-size: 0.875rem;
    color: var(--gray-500);
}

.course-actions {
    display: flex;
    gap: 0.75rem;
}

.course-actions .btn {
    flex: 1;
    padding: 0.625rem 1rem;
    font-size: 0.875rem;
}

.features-section {
    background: var(--white);
    padding: 4rem 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.feature-card {
    text-align: center;
    padding: 2rem;
}

.feature-icon {
    width: 64px;
    height: 64px;
    background: rgba(26, 42, 108, 0.08);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.25rem;
    color: var(--primary);
}

.feature-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 0.5rem;
}

.feature-card p {
    color: var(--gray-500);
    font-size: 0.9375rem;
}

.course-detail-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
    padding: 3rem 0;
}

.course-detail-image {
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: var(--gray-100);
}

.course-detail-image img {
    width: 100%;
    height: auto;
}

.course-detail-info h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: 1rem;
}

.course-description {
    color: var(--gray-600);
    font-size: 1.0625rem;
    line-height: 1.7;
    margin-bottom: 2rem;
}

.course-details {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--gray-100);
    border-radius: var(--radius);
    border-left: 3px solid var(--accent);
}

.detail-item {
    text-align: center;
}

.detail-label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--gray-500);
    margin-bottom: 0.25rem;
}

.detail-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
}

.week-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1rem;
}

.week-card {
    background: var(--white);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
    border-left: 3px solid var(--primary);
}

.week-number {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--accent-dark);
    margin-bottom: 0.5rem;
}

.week-card h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 1rem;
}

.week-items {
    list-style: none;
}

.week-items li {
    font-size: 0.875rem;
    color: var(--gray-600);
    padding: 0.375rem 0;
    padding-left: 1.25rem;
    position: relative;
}

.week-items li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 6px;
    background: var(--accent);
    border-radius: 50%;
}

.enrollment-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 1.5rem;
}

.enrollment-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    border-top: 3px solid var(--accent);
}

.enrollment-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1.25rem;
}

.enrollment-header h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--gray-800);
}

.status-badge {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 0.75rem;
    border-radius: 100px;
    text-transform: uppercase;
    letter-spacing: 0.025em;
}

.status-active {
    background: rgba(34, 197, 94, 0.1);
    color: var(--success);
}

.status-completed {
    background: rgba(26, 42, 108, 0.1);
    color: var(--primary);
}

.status-failed {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger);
}

.status-incomplete {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning);
}

.enrollment-progress {
    margin-bottom: 1rem;
}

.progress-bar {
    height: 8px;
    background: var(--gray-200);
    border-radius: 100px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
    border-radius: 100px;
    transition: width 0.3s;
}

.progress-text {
    font-size: 0.875rem;
    color: var(--gray-500);
}

.enrollment-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-bottom: 1rem;
}

.certificate-badge {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--gray-200);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--accent-dark);
}

.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--gray-500);
}

.empty-state svg {
    margin-bottom: 1.5rem;
    color: var(--gray-300);
}

.empty-state h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: 0.5rem;
}

.empty-state p {
    margin-bottom: 1.5rem;
}

.footer {
    background: var(--primary-dark);
    color: rgba(255, 255, 255, 0.6);
    padding: 3rem 1.5rem 1.5rem;
    font-size: 0.875rem;
    border-top: 3px solid var(--accent);
}

.footer-container {
    max-width: 1100px;
    margin: 0 auto;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 2.5rem;
    margin-bottom: 2rem;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
}

.footer-brand h3 {
    color: var(--white);
    font-size: 1.1rem;
    margin: 0;
}

.footer-logo {
    width: 40px !important;
    height: 40px !important;
    max-width: 40px !important;
    max-height: 40px !important;
    border-radius: 50%;
    object-fit: contain;
    background: var(--white);
    flex-shrink: 0;
}

.footer-description {
    line-height: 1.6;
    color: rgba(255, 255, 255, 0.5);
}

.footer-col h4 {
    color: var(--accent);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.footer-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-links li {
    margin-bottom: 0.5rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.6);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: var(--accent);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 1.25rem;
    text-align: center;
    color: rgba(255, 255, 255, 0.4);
    font-size: 0.8rem;
}

/* About page */
.about-page {
    background: var(--gray-100);
    min-height: 100vh;
}

.about-hero {
    text-align: center;
    padding: 3rem 0 2rem;
}

.about-logo {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    object-fit: contain;
    background: var(--white);
    box-shadow: var(--shadow);
    margin-bottom: 1.25rem;
}

.about-hero h1 {
    color: var(--primary);
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.about-subtitle {
    color: var(--accent);
    font-size: 1.1rem;
    font-weight: 500;
}

.about-content {
    max-width: 900px;
    margin: 0 auto;
    padding-bottom: 3rem;
}

.about-section {
    background: var(--white);
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-sm);
}

.about-section h2 {
    color: var(--primary);
    font-size: 1.35rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--accent);
    display: inline-block;
}

.about-section p {
    color: var(--gray-700);
    line-height: 1.7;
}

.about-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-top: 1.25rem;
}

.about-feature {
    text-align: center;
    padding: 1.25rem;
}

.about-feature-icon {
    width: 56px;
    height: 56px;
    background: rgba(26, 42, 108, 0.08);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    color: var(--primary);
}

.about-feature h3 {
    color: var(--primary);
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.about-feature p {
    font-size: 0.875rem;
    color: var(--gray-600);
}

.about-steps {
    margin-top: 1rem;
}

.about-step {
    display: flex;
    align-items: flex-start;
    gap: 1.25rem;
    padding: 1rem 0;
    border-bottom: 1px solid var(--gray-200);
}

.about-step:last-child {
    border-bottom: none;
}

.step-number {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    background: var(--primary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.95rem;
}

.about-step h3 {
    color: var(--primary);
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.about-step p {
    font-size: 0.9rem;
    margin: 0;
}

.about-contact {
    text-align: center;
}

/* Hamburger menu button - hidden on desktop */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius);
    transition: background 0.15s;
}

.nav-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
}

.nav-toggle .close-icon {
    display: none;
}

.nav-toggle.active .hamburger-icon {
    display: none;
}

.nav-toggle.active .close-icon {
    display: block;
}

.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    position: relative;
}

.login-page::before {
    content: '';
    position: fixed;
    top: -20px;
    left: -20px;
    right: -20px;
    bottom: -20px;
    background: url("../images/hero-bg.9c4d26affd58.jpg") center center / cover no-repeat;
    filter: blur(6px) brightness(0.35) saturate(0.7);
    z-index: 0;
}

.login-page::after {
    content: '';
    position: fixed;
    inset: 0;
    background: linear-gradient(135deg, rgba(26, 42, 108, 0.75) 0%, rgba(10, 18, 50, 0.85) 100%);
    z-index: 1;
}

.login-page > * {
    position: relative;
    z-index: 2;
}

.login-container {
    width: 100%;
    max-width: 420px;
}

.login-page:has(.register-card) .login-container {
    max-width: 560px;
}

span.required {
    color: var(--danger);
    font-weight: 600;
}

.login-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: 2.5rem;
    border-top: 4px solid var(--accent);
}

.login-logo {
    display: block;
    width: 80px;
    height: 80px;
    border-radius: 50%;
    object-fit: contain;
    margin: 0 auto 1.25rem;
    background: var(--white);
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.login-header p {
    color: var(--gray-500);
    font-size: 0.9375rem;
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--gray-700);
}

.form-group input {
    padding: 0.75rem 1rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(26, 42, 108, 0.1);
}

.form-select {
    padding: 0.75rem 1rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 1rem;
    background: var(--white);
    transition: border-color 0.2s, box-shadow 0.2s;
    width: 100%;
}

.login-footer {
    text-align: center;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--gray-200);
}

.login-footer p {
    font-size: 0.875rem;
    color: var(--gray-500);
}

.auth-link {
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
}

.auth-link:hover {
    text-decoration: underline;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
    min-width: 0;
}

.form-row .form-group {
    min-width: 0;
}

.form-row .form-group input {
    width: 100%;
}

.messages {
    margin-bottom: 1.5rem;
}

.alert {
    padding: 0.75rem 1rem;
    border-radius: var(--radius);
    font-size: 0.875rem;
}

.alert-error {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-name {
    font-weight: 500;
    color: var(--accent-light);
    text-decoration: none;
}

.user-name:hover {
    color: var(--accent);
}

.profile-card {
    max-width: 700px;
    margin: 0 auto;
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    box-shadow: var(--shadow);
    border-top: 3px solid var(--accent);
}

.profile-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-section-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--primary);
    margin-top: 0.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--gray-200);
}

.form-hint {
    font-size: 0.8125rem;
    color: var(--gray-500);
    margin-top: -0.5rem;
}

.form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 0.5rem;
}

.alert-success {
    background: rgba(34, 197, 94, 0.1);
    color: var(--success);
    border: 1px solid rgba(34, 197, 94, 0.2);
}

.alert-warning {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning);
    border: 1px solid rgba(245, 158, 11, 0.2);
}

.profile-image-section {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.profile-image-preview {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    overflow: hidden;
    flex-shrink: 0;
    border: 3px solid var(--gray-200);
}

.profile-image-preview img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.profile-image-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-100);
    color: var(--gray-400);
}

.profile-image-upload {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.file-input-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

.btn-upload {
    cursor: pointer;
    display: inline-block;
    width: auto;
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.8125rem;
}

.week-card.locked {
    opacity: 0.5;
    border-left-color: var(--gray-300);
}

.week-status {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 0.75rem;
    border-radius: 100px;
    margin-top: 1rem;
}

.week-status.available {
    background: rgba(34, 197, 94, 0.1);
    color: var(--success);
}

.week-status.locked {
    background: var(--gray-200);
    color: var(--gray-500);
}

.course-status-overlay {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 0.75rem;
    border-radius: 100px;
    text-transform: uppercase;
}

.status-assigned {
    background: rgba(197, 164, 78, 0.15);
    color: var(--accent-dark);
}

.enrollment-card.completed {
    border-top-color: var(--success);
}

.course-hero {
    background: var(--white);
    border-bottom: 3px solid var(--accent);
}

/* Week Detail - Sidebar Layout */
.week-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    min-height: calc(100vh - 64px);
}

.week-sidebar {
    background: var(--white);
    border-right: 1px solid var(--gray-200);
    padding: 0;
    position: sticky;
    top: 64px;
    height: calc(100vh - 64px);
    overflow-y: auto;
}

.sidebar-header {
    padding: 1.25rem 1.25rem 1rem;
    border-bottom: 1px solid var(--gray-200);
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    color: var(--gray-500);
    text-decoration: none;
    font-size: 0.8rem;
    font-weight: 500;
    margin-bottom: 0.75rem;
}

.back-link:hover {
    color: var(--primary);
}

.sidebar-title {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.week-badge {
    background: var(--primary);
    color: var(--white);
    padding: 0.2rem 0.65rem;
    border-radius: 100px;
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    display: inline-block;
    width: fit-content;
}

.sidebar-title h2 {
    font-size: 1.05rem;
    color: var(--primary);
    margin: 0;
    line-height: 1.3;
}

.week-complete-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: rgba(34, 197, 94, 0.1);
    color: var(--success);
    padding: 0.35rem 0.75rem;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 0.75rem;
    margin-top: 0.65rem;
}

.sidebar-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.85rem 1.25rem;
    text-decoration: none;
    color: var(--gray-600);
    border-left: 3px solid transparent;
    transition: all 0.15s;
    cursor: pointer;
}

.sidebar-item:hover {
    background: var(--gray-50);
    color: var(--primary);
}

.sidebar-item.active {
    background: rgba(26, 42, 108, 0.04);
    color: var(--primary);
    border-left-color: var(--primary);
    font-weight: 600;
}

.sidebar-icon {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.video-icon {
    background: rgba(239, 68, 68, 0.1);
    color: #ef4444;
}

.live-icon {
    background: rgba(59, 130, 246, 0.1);
    color: #3b82f6;
}

.quiz-icon {
    background: rgba(168, 85, 247, 0.1);
    color: #a855f7;
}

.assignment-icon {
    background: rgba(34, 197, 94, 0.1);
    color: #22c55e;
}

.sidebar-item-content {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex: 1;
    min-width: 0;
}

.sidebar-item-title {
    font-size: 0.85rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    flex-shrink: 0;
}

.status-dot.completed {
    background: var(--success);
}

.status-dot.pending {
    background: var(--gray-300);
}

.status-dot.current {
    background: var(--accent);
    box-shadow: 0 0 0 3px rgba(197, 164, 78, 0.25);
}

.status-dot.locked {
    background: var(--gray-200);
    border: 1.5px solid var(--gray-300);
}

.sidebar-item.locked {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.sidebar-item.locked .sidebar-icon {
    background: var(--gray-100);
    color: var(--gray-400);
}

.sidebar-nav {
    padding: 0.5rem 0;
    position: relative;
}

.step-connector {
    position: absolute;
    left: 42px;
    top: 45px;
    bottom: 45px;
    width: 2px;
    background: var(--gray-200);
    z-index: 0;
}

.locked-message {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    padding: 3rem 2rem;
    text-align: center;
    color: var(--gray-400);
}

.locked-message p {
    font-size: 1rem;
    color: var(--gray-500);
    max-width: 360px;
}

.status-tag.locked-tag {
    background: var(--gray-100);
    color: var(--gray-500);
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}

.step-next-hint {
    font-size: 0.8rem;
    color: var(--accent);
    margin-top: 0.5rem;
    font-weight: 500;
}

.week-progress-hint {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    background: rgba(26, 42, 108, 0.04);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    color: var(--gray-600);
    font-size: 0.9rem;
}

.controlled-player {
    border-radius: var(--radius);
    overflow: hidden;
    background: #000;
    margin-bottom: 1rem;
}

.controlled-player .video-container {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    background: #000;
}

.controlled-player .video-container iframe,
.controlled-player .video-container video,
.controlled-player .video-container > div:first-child {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.controlled-player video {
    object-fit: contain;
}

.player-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 5;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

.play-overlay-btn {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    background: rgba(26, 42, 108, 0.85);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    transition: transform 0.2s, background 0.2s;
    opacity: 0;
    pointer-events: none;
}

.player-overlay:hover .play-overlay-btn {
    opacity: 1;
}

.player-controls {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.6rem 1rem;
    background: var(--primary);
    color: white;
}

.player-btn {
    background: none;
    border: none;
    color: white;
    cursor: pointer;
    padding: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 4px;
    transition: background 0.15s;
}

.player-btn:hover {
    background: rgba(255, 255, 255, 0.15);
}

.player-time {
    font-size: 0.8rem;
    font-variant-numeric: tabular-nums;
    white-space: nowrap;
    min-width: 90px;
}

.player-progress-bar {
    flex: 1;
    min-width: 0;
}

.player-progress-track {
    height: 8px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    overflow: hidden;
    cursor: pointer;
    position: relative;
}

.player-progress-track:hover {
    height: 10px;
}

.player-progress-buffered {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    background: rgba(197, 164, 78, 0.35);
    border-radius: 3px;
    z-index: 1;
    pointer-events: none;
}

.player-progress-fill {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    background: var(--accent);
    border-radius: 3px;
    transition: width 0.3s ease;
    z-index: 2;
    pointer-events: none;
}

.player-pct {
    font-size: 0.8rem;
    font-weight: 600;
    min-width: 35px;
    text-align: right;
}

.volume-slider {
    width: 70px;
    height: 4px;
    -webkit-appearance: none;
    appearance: none;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
}

.volume-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: white;
    cursor: pointer;
}

.volume-slider::-moz-range-thumb {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: white;
    border: none;
    cursor: pointer;
}

.video-complete-ready {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    align-items: flex-start;
}

.video-rules {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    padding: 0.6rem 0.85rem;
    background: rgba(245, 158, 11, 0.06);
    border: 1px solid rgba(245, 158, 11, 0.15);
    border-radius: var(--radius);
    color: #92400e;
    font-size: 0.8rem;
    margin-bottom: 1rem;
}

.video-rules svg {
    flex-shrink: 0;
    margin-top: 1px;
}

.video-watch-prompt {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: rgba(26, 42, 108, 0.04);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    color: var(--gray-600);
    font-size: 0.9rem;
}

.attendance-confirmed {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: rgba(34, 197, 94, 0.08);
    border: 1px solid rgba(34, 197, 94, 0.2);
    border-radius: var(--radius);
    color: var(--success);
    font-size: 0.9rem;
    font-weight: 500;
}

.attendance-pending {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: rgba(245, 158, 11, 0.08);
    border: 1px solid rgba(245, 158, 11, 0.2);
    border-radius: var(--radius);
    color: #b45309;
    font-size: 0.9rem;
}

.attendance-toggle-form {
    display: inline;
}

.attendance-toggle {
    background: none;
    border: 2px solid transparent;
    border-radius: 6px;
    cursor: pointer;
    padding: 4px;
    transition: all 0.15s;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
}

.attendance-toggle.present {
    color: var(--success);
    background: rgba(34, 197, 94, 0.1);
    border-color: rgba(34, 197, 94, 0.3);
}

.attendance-toggle.present:hover {
    background: rgba(239, 68, 68, 0.1);
    border-color: rgba(239, 68, 68, 0.3);
    color: #ef4444;
}

.attendance-toggle.absent {
    color: var(--gray-400);
    background: var(--gray-50);
    border-color: var(--gray-200);
}

.attendance-toggle.absent:hover {
    background: rgba(34, 197, 94, 0.1);
    border-color: rgba(34, 197, 94, 0.3);
    color: var(--success);
}

/* Main content area */
.week-main {
    padding: 2rem 2.5rem;
    background: var(--gray-50);
    overflow-y: auto;
}

.week-section {
    display: none;
}

.week-section.active {
    display: block;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.section-header h2 {
    font-size: 1.5rem;
    color: var(--primary);
    margin: 0;
}

.status-tag {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.3rem 0.75rem;
    border-radius: 100px;
}

.status-tag.completed {
    background: rgba(34, 197, 94, 0.1);
    color: var(--success);
}

.status-tag.pending {
    background: var(--gray-200);
    color: var(--gray-500);
}

.section-body {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
}

.video-container {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%;
    border-radius: var(--radius);
    overflow: hidden;
    background: #000;
    margin-bottom: 1rem;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.content-meta {
    font-size: 0.8125rem;
    color: var(--gray-500);
    margin-top: 0.5rem;
}

.content-empty {
    text-align: center;
    padding: 2.5rem 1rem;
    color: var(--gray-400);
}

.content-empty svg {
    margin-bottom: 0.75rem;
    opacity: 0.5;
}

.content-empty p {
    font-style: italic;
    font-size: 0.95rem;
}

.section-actions {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--gray-200);
}

.detail-card {
    background: var(--gray-50);
    border-radius: var(--radius);
    padding: 1.25rem;
    margin-bottom: 1rem;
}

.detail-card h3 {
    color: var(--primary);
    font-size: 1.05rem;
    margin-bottom: 0.4rem;
}

.detail-card p {
    color: var(--gray-600);
    font-size: 0.9rem;
    line-height: 1.6;
}

.live-class-details .info-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 0;
    color: var(--gray-700);
}

.live-class-details .info-row + .info-row {
    border-top: 1px solid var(--gray-200);
}

.live-class-details .info-row svg {
    color: var(--primary);
    flex-shrink: 0;
}

.info-label {
    display: block;
    font-size: 0.75rem;
    color: var(--gray-500);
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.info-value {
    display: block;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--gray-800);
}

.recording-section {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--gray-200);
}

.recording-heading {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.assignment-form {
    margin-top: 1rem;
}

.assignment-form .form-group {
    margin-bottom: 1rem;
}

.btn-disabled {
    background: var(--gray-200) !important;
    color: var(--gray-400) !important;
    border: 1px solid var(--gray-200) !important;
    cursor: not-allowed;
    opacity: 0.7;
}

.disabled-hint {
    font-size: 0.8rem;
    color: var(--gray-400);
    margin-top: 0.5rem;
    font-style: italic;
}

.btn-undo {
    color: var(--gray-500);
    border-color: var(--gray-300);
    font-size: 0.8rem;
}

.btn-undo:hover {
    color: var(--danger);
    border-color: var(--danger);
    background: rgba(239, 68, 68, 0.05);
}

.week-complete-action {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 2px solid var(--gray-200);
    text-align: center;
}

.btn-lg {
    padding: 0.75rem 2rem;
    font-size: 1rem;
}

.btn-complete-week {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.week-done-banner {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.65rem;
    background: rgba(34, 197, 94, 0.08);
    color: var(--success);
    padding: 1rem 1.5rem;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(34, 197, 94, 0.2);
    font-weight: 600;
    font-size: 0.95rem;
}

/* Week items in course detail */
.week-items li {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.week-items li svg {
    color: var(--gray-400);
    flex-shrink: 0;
}

.week-status.locked {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}

/* Trainer Pages */
.trainer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 1.5rem;
}

.trainer-course-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
    overflow: hidden;
}

.trainer-card-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.75rem;
}

.trainer-card-header h3 {
    margin: 0;
    font-size: 1.05rem;
    color: var(--primary);
}

.trainer-card-stats {
    display: flex;
    padding: 1.25rem 1.5rem;
    gap: 1.5rem;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-number {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-number.active-num {
    color: #3b82f6;
}

.stat-number.completed-num {
    color: var(--success);
}

.stat-label {
    font-size: 0.75rem;
    color: var(--gray-500);
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.trainer-card-actions {
    padding: 0 1.5rem 1.25rem;
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.trainer-card-accent {
    border-left: 4px solid var(--primary);
}

.page-subtitle {
    color: var(--gray-500);
    font-size: 0.95rem;
    margin-top: 0.25rem;
}

.progress-table-wrap {
    overflow-x: auto;
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.data-table thead th {
    background: var(--primary);
    color: #fff;
    padding: 0.75rem 1rem;
    text-align: left;
    font-weight: 600;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    white-space: nowrap;
}

.data-table tbody td {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--gray-100);
    color: var(--gray-700);
}

.data-table tbody tr:hover {
    background: var(--gray-50);
}

.week-col {
    text-align: center;
    min-width: 50px;
}

.th-date {
    display: block;
    font-size: 0.65rem;
    font-weight: 400;
    text-transform: none;
    opacity: 0.8;
}

.learner-name {
    white-space: nowrap;
}

.week-check {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    border-radius: 50%;
}

.week-check.done {
    color: var(--success);
}

.week-check.partial {
    color: var(--accent);
}

.week-check.empty {
    color: var(--gray-300);
}

.week-check.absent {
    color: #ef4444;
}

.status-pill {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 0.2rem 0.6rem;
    border-radius: 100px;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.status-pill.status-active {
    background: rgba(59, 130, 246, 0.1);
    color: #3b82f6;
}

.status-pill.status-assigned {
    background: var(--gray-100);
    color: var(--gray-500);
}

.status-pill.status-completed {
    background: rgba(34, 197, 94, 0.1);
    color: var(--success);
}

.rate-badge {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 700;
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius);
}

.rate-good {
    background: rgba(34, 197, 94, 0.1);
    color: var(--success);
}

.rate-mid {
    background: rgba(234, 179, 8, 0.1);
    color: #ca8a04;
}

.rate-low {
    background: rgba(239, 68, 68, 0.1);
    color: #ef4444;
}

.filter-bar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.filter-label {
    font-size: 0.85rem;
    color: var(--gray-500);
    font-weight: 500;
}

.filter-chip {
    display: inline-block;
    padding: 0.35rem 0.85rem;
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 500;
    text-decoration: none;
    color: var(--gray-600);
    background: var(--gray-100);
    transition: all 0.15s;
}

.filter-chip:hover {
    background: var(--gray-200);
    color: var(--primary);
}

.filter-chip.active {
    background: var(--primary);
    color: #fff;
}

.submissions-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.submission-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
    padding: 1.25rem 1.5rem;
}

.submission-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
    flex-wrap: wrap;
}

.submission-info h3 {
    margin: 0;
    font-size: 1rem;
    color: var(--primary);
}

.submission-meta {
    font-size: 0.8rem;
    color: var(--gray-500);
    margin-top: 0.15rem;
}

.submission-value {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 0.25rem;
}

.value-badge {
    background: rgba(26, 42, 108, 0.08);
    color: var(--primary);
    font-weight: 600;
    font-size: 0.85rem;
    padding: 0.2rem 0.6rem;
    border-radius: var(--radius);
}

.submission-date {
    font-size: 0.75rem;
    color: var(--gray-400);
}

.comments-section {
    margin-top: 1rem;
    padding-top: 0.75rem;
    border-top: 1px solid var(--gray-200);
}

.comment {
    background: var(--gray-50);
    border-radius: var(--radius);
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
}

.comment-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.25rem;
    font-size: 0.8rem;
}

.comment-header strong {
    color: var(--primary);
}

.comment-date {
    color: var(--gray-400);
    font-size: 0.7rem;
}

.comment p {
    margin: 0;
    font-size: 0.875rem;
    color: var(--gray-700);
    line-height: 1.5;
}

.comment-form {
    margin-top: 0.75rem;
}

.comment-input-row {
    display: flex;
    gap: 0.5rem;
}

.comment-input {
    flex: 1;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 0.85rem;
    color: var(--gray-700);
}

.comment-input:focus {
    border-color: var(--primary);
    outline: none;
    box-shadow: 0 0 0 2px rgba(26, 42, 108, 0.1);
}

.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--gray-400);
}

.empty-state h3 {
    color: var(--gray-600);
    margin-top: 1rem;
    margin-bottom: 0.5rem;
}

.empty-state p {
    color: var(--gray-400);
    font-size: 0.95rem;
}

/* ============ MOBILE RESPONSIVE ============ */

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .nav-container {
        height: 56px;
        padding: 0 1rem;
    }

    .nav-brand {
        font-size: 1rem;
        gap: 0.5rem;
    }

    .nav-logo {
        width: 30px;
        height: 30px;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 56px;
        left: 0;
        right: 0;
        background: var(--primary-dark);
        flex-direction: column;
        padding: 0.5rem 0;
        box-shadow: 0 8px 16px rgba(0,0,0,0.2);
        z-index: 99;
        gap: 0;
    }

    .nav-links.open {
        display: flex;
    }

    .nav-links a {
        padding: 0.85rem 1.5rem;
        border-bottom: 1px solid rgba(255,255,255,0.06);
        width: 100%;
    }

    .nav-links a:hover {
        background: rgba(255,255,255,0.05);
    }

    .user-menu {
        flex-direction: column;
        align-items: flex-start;
        padding: 0.85rem 1.5rem;
        gap: 0.75rem;
    }

    .navbar {
        position: relative;
    }

    .hero {
        padding: 2.5rem 1rem;
    }

    .hero h1 {
        font-size: 1.75rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .container {
        padding: 0 1rem;
    }

    .course-grid,
    .enrollment-grid {
        grid-template-columns: 1fr;
    }

    .course-detail-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        padding: 1.5rem 0;
    }

    .course-details {
        grid-template-columns: repeat(3, 1fr);
        gap: 0.75rem;
        padding: 1rem;
    }

    .course-detail-info h1 {
        font-size: 1.5rem;
    }

    .week-grid {
        grid-template-columns: 1fr;
    }

    .trainer-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .about-features {
        grid-template-columns: 1fr;
    }

    .about-hero h1 {
        font-size: 1.5rem;
    }

    .about-hero p {
        font-size: 0.95rem;
    }

    .profile-card {
        padding: 1.5rem;
        margin: 0 0.5rem;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .profile-image-section {
        flex-direction: column;
        align-items: flex-start;
    }

    .week-layout {
        grid-template-columns: 1fr;
    }

    .week-sidebar {
        position: relative;
        top: 0;
        height: auto;
        border-right: none;
        border-bottom: 1px solid var(--gray-200);
    }

    .sidebar-nav {
        display: flex;
        overflow-x: auto;
        padding: 0;
        -webkit-overflow-scrolling: touch;
    }

    .sidebar-nav::-webkit-scrollbar {
        display: none;
    }

    .step-connector {
        display: none;
    }

    .sidebar-item {
        border-left: none;
        border-bottom: 3px solid transparent;
        padding: 0.75rem 1rem;
        white-space: nowrap;
        flex-shrink: 0;
    }

    .sidebar-item.active {
        border-left-color: transparent;
        border-bottom-color: var(--primary);
    }

    .sidebar-icon {
        width: 28px;
        height: 28px;
    }

    .sidebar-icon svg {
        width: 14px;
        height: 14px;
    }

    .week-main {
        padding: 1.25rem 1rem;
    }

    .section-body {
        padding: 1.25rem;
    }

    .section-header h2 {
        font-size: 1.2rem;
    }

    .player-controls {
        flex-wrap: wrap;
        gap: 0.5rem;
        padding: 0.5rem 0.75rem;
    }

    .player-time {
        font-size: 0.7rem;
        min-width: 70px;
    }

    .volume-slider {
        width: 50px;
    }

    .play-overlay-btn {
        width: 56px;
        height: 56px;
    }

    .login-card {
        padding: 1.75rem 1.25rem;
    }

    .login-logo {
        width: 64px;
        height: 64px;
    }

    .login-header h1 {
        font-size: 1.25rem;
    }

    .data-table {
        font-size: 0.8rem;
    }

    .data-table thead th {
        padding: 0.5rem 0.65rem;
        font-size: 0.7rem;
    }

    .data-table tbody td {
        padding: 0.5rem 0.65rem;
    }

    .submission-header {
        flex-direction: column;
        gap: 0.5rem;
    }

    .submission-value {
        align-items: flex-start;
    }

    .filter-bar {
        gap: 0.35rem;
    }

    .filter-chip {
        padding: 0.3rem 0.65rem;
        font-size: 0.75rem;
    }

    .btn-lg {
        padding: 0.65rem 1.5rem;
        font-size: 0.9rem;
    }

    .comment-input-row {
        flex-direction: column;
    }

    .main-content {
        min-height: calc(100vh - 56px);
    }

    .trainer-card-stats {
        flex-wrap: wrap;
        gap: 1rem;
        padding: 1rem;
    }

    .trainer-card-actions {
        padding: 0 1rem 1rem;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.5rem;
    }

    .course-details {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }

    .detail-item {
        display: flex;
        justify-content: space-between;
        align-items: center;
        text-align: left;
    }

    .btn {
        padding: 0.65rem 1.25rem;
        font-size: 0.875rem;
    }

    .btn-full {
        width: 100%;
    }

    .form-actions {
        flex-direction: column;
    }

    .form-actions .btn {
        width: 100%;
    }

    .week-progress-hint {
        flex-direction: column;
        text-align: center;
        padding: 0.75rem 1rem;
    }
}