/* ============================================
   Design Tokens & Variables
   ============================================ */
:root {
    /* Colors */
    --color-primary: #4A7C8C;
    --color-secondary: #2F5A68;
    --color-accent: #F59E0B;
    --color-background: #FFFBEB;
    --color-surface: #FFFFFF;
    --color-text: #1F2937;
    --color-text-secondary: #6B7280;
    --color-success: #10B981;
    --color-error: #EF4444;

    /* Typography */
    --font-primary: 'Source Sans Pro', system-ui, sans-serif;
    --font-secondary: 'Merriweather', Georgia, serif;
    --font-size-xs: 0.8rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-md: 1.25rem;
    --font-size-lg: 1.563rem;
    --font-size-xl: 1.953rem;
    --font-size-2xl: 2.441rem;
    --font-size-3xl: 3.052rem;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;

    /* Border Radius - Standardized */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08), 0 2px 6px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1), 0 6px 12px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.12), 0 10px 20px rgba(0, 0, 0, 0.06);

    /* Animation */
    --animation-duration: 0.6s;
    --animation-timing: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================
   Accessibility - Screen Reader Only
   ============================================ */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Skip Link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary, #4A7C8C);
    color: #fff;
    padding: 8px 16px;
    text-decoration: none;
    z-index: 1000;
    border-radius: 0 0 4px 0;
}

.skip-link:focus {
    top: 0;
}

.back-to-catalog {
    position: fixed;
    top: 1rem;
    left: 1rem;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: #4A7C8C;
    background: rgba(255, 255, 255, 0.95);
    border: 1px solid #E8E4DD;
    border-radius: 6px;
    text-decoration: none;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: all 0.2s ease;
}

.back-to-catalog:hover {
    background: #4A7C8C;
    color: white;
    border-color: #4A7C8C;
}

.back-to-catalog:focus {
    outline: 2px solid #4A7C8C;
    outline-offset: 2px;
}

/* ============================================
   Reset & Base Styles
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-primary);
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-background);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-secondary);
    line-height: 1.25;
    font-weight: 700;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    position: relative;
    width: 100%;
    min-height: 70vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-3xl) var(--spacing-md);
    background: linear-gradient(135deg, var(--color-background) 0%, #FEF3C7 50%, var(--color-background) 100%);
    animation: heroFadeIn var(--animation-duration) var(--animation-timing);
}

@keyframes heroFadeIn {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.hero__container {
    max-width: 1000px;
    width: 100%;
    text-align: center;
}

.hero__headline {
    font-size: var(--font-size-2xl);
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
    animation: headlineFadeIn var(--animation-duration) var(--animation-timing) 0.1s backwards;
}

.hero__headline-emphasis {
    color: var(--color-primary);
    display: inline-block;
    position: relative;
}

.hero__headline-emphasis::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    opacity: 0.3;
    border-radius: 2px;
}

.hero__subheadline {
    font-size: var(--font-size-md);
    color: var(--color-text-secondary);
    max-width: 720px;
    margin: 0 auto;
    animation: subheadlineFadeIn var(--animation-duration) var(--animation-timing) 0.2s backwards;
}

@keyframes headlineFadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes subheadlineFadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ============================================
   Courses Section
   ============================================ */
.courses {
    padding: var(--spacing-3xl) var(--spacing-md);
    background-color: var(--color-surface);
}

.courses__container {
    max-width: 1400px;
    margin: 0 auto;
}

.courses__heading {
    font-size: var(--font-size-xl);
    color: var(--color-text);
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.courses__grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
}

/* ============================================
   Course Card
   ============================================ */
.course-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all 0.4s var(--animation-timing);
    cursor: pointer;
    opacity: 0;
    animation: cardFadeIn 0.6s var(--animation-timing) forwards;
}

@keyframes cardFadeIn {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.course-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.course-card__image-wrapper {
    position: relative;
    width: 100%;
    padding-top: 56.25%; /* 16:9 aspect ratio */
    overflow: hidden;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
}

.course-card__image {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s var(--animation-timing);
}

.course-card:hover .course-card__image {
    transform: scale(1.05);
}

.course-card__badge {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: rgba(255, 255, 255, 0.95);
    color: var(--color-primary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-xs);
    font-weight: 600;
    backdrop-filter: blur(10px);
}

.course-card__content {
    padding: var(--spacing-xl);
}

.course-card__duration {
    display: inline-block;
    font-size: var(--font-size-xs);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.course-card__title {
    font-size: var(--font-size-lg);
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
    font-family: var(--font-secondary);
}

.course-card__description {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.7;
}

.course-card__instructor {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(0, 0, 0, 0.08);
}

.course-card__instructor-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--color-primary);
}

.course-card__instructor-info {
    flex: 1;
}

.course-card__instructor-name {
    font-weight: 600;
    color: var(--color-text);
    display: block;
    margin-bottom: 2px;
}

.course-card__instructor-title {
    font-size: var(--font-size-xs);
    color: var(--color-text-secondary);
}

.course-card__cta {
    margin-top: var(--spacing-lg);
}

/* ============================================
   Modal
   ============================================ */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
    opacity: 0;
    animation: modalFadeIn 0.3s var(--animation-timing) forwards;
}

@keyframes modalFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal__overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(8px);
}

.modal__content {
    position: relative;
    width: 100%;
    max-width: 900px;
    max-height: 90vh;
    background: var(--color-surface);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow-y: auto;
    animation: modalSlideIn 0.4s var(--animation-timing);
}

@keyframes modalSlideIn {
    from { transform: translateY(30px) scale(0.95); }
    to { transform: translateY(0) scale(1); }
}

.modal__content--form {
    max-width: 700px;
}

.modal__close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.05);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.2s var(--animation-timing);
    color: var(--color-text-secondary);
    z-index: 10;
}

.modal__close:hover {
    background: rgba(0, 0, 0, 0.1);
    transform: rotate(90deg);
}

.modal__close:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* ============================================
   Course Detail
   ============================================ */
.course-detail {
    padding: var(--spacing-xl);
}

.course-detail__header {
    margin-bottom: var(--spacing-xl);
}

.course-detail__image {
    width: 100%;
    height: 400px;
    object-fit: cover;
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

.course-detail__title {
    font-size: var(--font-size-xl);
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

.course-detail__meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.course-detail__description {
    font-size: var(--font-size-md);
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-xl);
}

.course-detail__section {
    margin-bottom: var(--spacing-xl);
}

.course-detail__section-title {
    font-size: var(--font-size-lg);
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

.course-detail__curriculum {
    list-style: none;
}

.course-detail__curriculum-item {
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    background: var(--color-background);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.course-detail__curriculum-icon {
    color: var(--color-primary);
    font-size: 1.2em;
}

.course-detail__instructor-card {
    display: flex;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    background: var(--color-background);
    border-radius: var(--radius-md);
}

.course-detail__instructor-avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--color-primary);
}

.course-detail__instructor-bio {
    flex: 1;
}

.course-detail__instructor-name {
    font-size: var(--font-size-lg);
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.course-detail__instructor-title {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.course-detail__instructor-description {
    color: var(--color-text-secondary);
    line-height: 1.7;
}

.course-detail__actions {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid rgba(0, 0, 0, 0.08);
}

/* ============================================
   Booking Form
   ============================================ */
.booking-form {
    padding: var(--spacing-xl);
}

.progress {
    margin-bottom: var(--spacing-xl);
}

.progress__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.time-estimate {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    font-weight: 500;
}

.progress__reassurance {
    text-align: center;
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-top: var(--spacing-sm);
    font-style: italic;
}

.progress__steps {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-md);
}

.progress__step {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    flex: 1;
    position: relative;
}

.progress__step:not(:last-child)::after {
    content: '';
    position: absolute;
    top: 16px;
    left: calc(50% + 20px);
    width: calc(100% - 40px);
    height: 2px;
    background: rgba(0, 0, 0, 0.1);
    z-index: 0;
}

.progress__step--active .progress__step-number {
    background: var(--color-primary);
    color: white;
    transform: scale(1.1);
}

.progress__step--completed .progress__step-number {
    background: var(--color-success);
    color: white;
}

.progress__step--completed .progress__step-number::after {
    content: '✓';
    position: absolute;
    color: white;
    font-weight: bold;
    font-size: 1.2em;
}

.progress__step-number {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.1);
    color: var(--color-text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    transition: all 0.3s var(--animation-timing);
    position: relative;
    z-index: 1;
}

.progress__step-label {
    font-size: var(--font-size-xs);
    color: var(--color-text-secondary);
    text-align: center;
}

.progress__step--active .progress__step-label {
    color: var(--color-primary);
    font-weight: 600;
}

.progress__bar {
    height: 6px;
    background: rgba(0, 0, 0, 0.08);
    border-radius: 3px;
    overflow: hidden;
}

.progress__bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    transition: width 0.5s var(--animation-timing);
}

.form-step {
    animation: formStepFadeIn 0.4s var(--animation-timing);
}

@keyframes formStepFadeIn {
    from { opacity: 0; transform: translateX(20px); }
    to { opacity: 1; transform: translateX(0); }
}

.form-step__title {
    font-size: var(--font-size-xl);
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
}

.form-step__description {
    font-size: var(--font-size-md);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.form-input {
    width: 100%;
    padding: var(--spacing-md);
    font-size: var(--font-size-sm);
    font-family: var(--font-primary);
    color: var(--color-text);
    background: var(--color-surface);
    border: 2px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--radius-sm);
    transition: all 0.2s var(--animation-timing);
}

.form-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(74, 124, 140, 0.1);
}

.form-input--textarea {
    resize: vertical;
    min-height: 120px;
}

.form-error {
    display: block;
    color: var(--color-error);
    font-size: var(--font-size-xs);
    margin-top: var(--spacing-xs);
}

.form-help {
    display: block;
    color: var(--color-text-secondary);
    font-size: var(--font-size-xs);
    margin-top: var(--spacing-xs);
}

.form-actions {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.booking-summary {
    background: var(--color-background);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-xl);
}

.booking-summary__item {
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.booking-summary__item:last-child {
    border-bottom: none;
}

.booking-summary__label {
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.booking-summary__value {
    color: var(--color-text-secondary);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-sm);
    font-weight: 600;
    font-family: var(--font-primary);
    text-decoration: none;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.3s var(--animation-timing);
    white-space: nowrap;
}

.btn--primary {
    background: var(--color-primary);
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn--primary:hover {
    background: var(--color-secondary);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.btn--primary:active {
    transform: translateY(0);
}

.btn--primary:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 3px;
}

.btn--secondary {
    background: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

.btn--secondary:hover {
    background: var(--color-primary);
    color: white;
}

.btn--secondary:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 3px;
}

.btn--link {
    background: transparent;
    color: var(--color-primary);
    padding: var(--spacing-sm) var(--spacing-md);
}

.btn--link:hover {
    background: rgba(74, 124, 140, 0.1);
}

.btn__icon {
    font-size: 1.2em;
    transition: transform 0.2s var(--animation-timing);
}

.btn--primary:hover .btn__icon {
    transform: translateX(3px);
}

.btn--secondary:hover .btn__icon {
    transform: translateX(-3px);
}

/* ============================================
   Confirmation Page
   ============================================ */
.confirmation {
    min-height: 100vh;
    padding: var(--spacing-3xl) var(--spacing-md);
    background: linear-gradient(135deg, var(--color-background) 0%, #FEF3C7 100%);
    animation: confirmationFadeIn 0.6s var(--animation-timing);
}

@keyframes confirmationFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.confirmation__container {
    max-width: 1000px;
    margin: 0 auto;
}

.confirmation__celebration {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.celebration__icon {
    margin: 0 auto var(--spacing-lg);
    animation: celebrationBounce 0.8s var(--animation-timing);
}

@keyframes celebrationBounce {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.confirmation__title {
    font-size: var(--font-size-3xl);
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
    animation: titleSlideIn 0.6s var(--animation-timing) 0.2s backwards;
}

@keyframes titleSlideIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.confirmation__message {
    font-size: var(--font-size-md);
    color: var(--color-text-secondary);
    animation: messageSlideIn 0.6s var(--animation-timing) 0.3s backwards;
}

@keyframes messageSlideIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.confirmation__details {
    background: var(--color-surface);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-xl);
    animation: detailsSlideIn 0.6s var(--animation-timing) 0.4s backwards;
}

@keyframes detailsSlideIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.confirmation__actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-3xl);
    animation: actionsSlideIn 0.6s var(--animation-timing) 0.5s backwards;
}

@keyframes actionsSlideIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.next-steps {
    margin-bottom: var(--spacing-3xl);
}

.next-steps__title {
    font-size: var(--font-size-xl);
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.next-steps__grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
}

.next-step-card {
    display: block;
    padding: var(--spacing-lg);
    background: var(--color-surface);
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: all 0.3s var(--animation-timing);
    box-shadow: var(--shadow-sm);
}

.next-step-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.next-step-card__icon {
    font-size: 2em;
    margin-bottom: var(--spacing-sm);
}

.next-step-card__title {
    font-size: var(--font-size-md);
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.next-step-card__description {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

.related-courses {
    margin-top: var(--spacing-3xl);
}

.related-courses__title {
    font-size: var(--font-size-xl);
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.related-courses__carousel {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
}

/* ============================================
   Toast Notification
   ============================================ */
.toast {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 2000;
    animation: toastSlideIn 0.3s var(--animation-timing);
}

@keyframes toastSlideIn {
    from { transform: translateX(400px); }
    to { transform: translateX(0); }
}

.toast__content {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-text);
    color: white;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-lg);
}

.toast__icon {
    font-size: 1.2em;
}

.toast__message {
    font-weight: 500;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (min-width: 640px) {
    .hero {
        min-height: 80vh;
    }

    .hero__headline {
        font-size: var(--font-size-3xl);
    }

    .courses__grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .next-steps__grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .related-courses__carousel {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .courses__grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .next-steps__grid {
        grid-template-columns: repeat(4, 1fr);
    }

    .related-courses__carousel {
        grid-template-columns: repeat(3, 1fr);
    }

    .form-actions {
        justify-content: flex-end;
    }

    .course-detail__instructor-card {
        align-items: center;
    }
}

/* ============================================
   Accessibility
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    margin: -1px;
    padding: 0;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

*:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* ============================================
   Loading Skeleton States
   ============================================ */
.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: skeleton-pulse 1.5s ease-in-out infinite;
    border-radius: var(--radius-sm);
}

@keyframes skeleton-pulse {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* Skeleton Card (for grid loading states) */
.skeleton-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.skeleton-content {
    padding: var(--spacing-xl);
}

.skeleton-image {
    width: 100%;
    height: 200px;
}

.skeleton-title {
    height: 24px;
    width: 70%;
    margin: 16px 0 8px;
}

.skeleton-text {
    height: 16px;
    margin: 8px 0;
}

.skeleton-text.short {
    width: 50%;
}

/* Skeleton Detail (for modal loading states) */
.course-detail--skeleton {
    padding: var(--spacing-xl);
}

.skeleton-detail-image {
    width: 100%;
    height: 400px;
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

.skeleton-detail-title {
    height: 36px;
    width: 80%;
    margin-bottom: var(--spacing-md);
}

.skeleton-detail-subtitle {
    height: 28px;
    width: 40%;
    margin-bottom: var(--spacing-md);
}

.skeleton-detail-meta {
    height: 20px;
    width: 60%;
    margin-bottom: var(--spacing-lg);
}

.skeleton-detail-text {
    height: 18px;
    margin-bottom: var(--spacing-md);
}

.skeleton-detail-text.short {
    width: 65%;
}

.skeleton-detail-list-item {
    height: 48px;
    margin-bottom: var(--spacing-sm);
    border-radius: var(--radius-sm);
}

.skeleton-detail-instructor {
    height: 120px;
    border-radius: var(--radius-md);
}

/* ============================================
   Utility Classes
   ============================================ */
[hidden] {
    display: none !important;
}

.fade-in {
    animation: fadeIn 0.4s var(--animation-timing);
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.slide-up {
    animation: slideUp 0.4s var(--animation-timing);
}

@keyframes slideUp {
    from { transform: translateY(20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}