/* CSS Variables */
:root {
    --primary-color: #4F46E5;
    --primary-dark: #3730A3;
    --secondary-color: #06B6D4;
    --success-color: #10B981;
    --warning-color: #F59E0B;
    --danger-color: #EF4444;
    --text-primary: #1F2937;
    --text-secondary: #6B7280;
    --text-light: #9CA3AF;
    --bg-primary: #FFFFFF;
    --bg-secondary: #F9FAFB;
    --bg-tertiary: #F3F4F6;
    --border-color: #E5E7EB;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
}

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

body {
    font-family: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    overflow-x: hidden;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.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;
}

/* Splash Screen */
.splash {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    color: white;
}

.splash-content {
    text-align: center;
    animation: fadeInUp 0.8s ease-out;
}

.splash .logo {
    font-size: 4rem;
    margin-bottom: 1rem;
    animation: pulse 2s infinite;
}

.splash h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.splash p {
    font-size: 1.1rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top: 3px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

/* App Layout */
.app {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem;
    max-width: 600px;
    margin: 0 auto;
}

.app-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.menu-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius-md);
    transition: all 0.2s;
}

.menu-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

/* Navigation */
.nav-menu {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 70px;
    z-index: 99;
    box-shadow: var(--shadow-sm);
}

.nav-menu.hidden {
    display: none;
}

.nav-menu ul {
    list-style: none;
    display: flex;
    max-width: 600px;
    margin: 0 auto;
}

.nav-menu li {
    flex: 1;
}

.nav-link {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem;
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: all 0.2s;
    border-bottom: 3px solid transparent;
}

.nav-link:hover {
    color: var(--primary-color);
    background: var(--bg-secondary);
}

.nav-link.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* Main Content */
.main-content {
    flex: 1;
    max-width: 600px;
    margin: 0 auto;
    width: 100%;
    padding: 0 1rem;
}

.screen {
    display: none;
    padding: 2rem 0;
    animation: fadeIn 0.3s ease-out;
}

.screen.active {
    display: block;
}

.screen h2 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    text-align: center;
    color: var(--text-primary);
}

/* Progress Ring */
.progress-ring-container {
    display: flex;
    justify-content: center;
    margin-bottom: 2rem;
}

.progress-ring {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.progress-circle {
    transform: rotate(-90deg);
}

.progress-track {
    fill: none;
    stroke: var(--bg-tertiary);
    stroke-width: 8;
}

.progress-bar {
    fill: none;
    stroke: var(--primary-color);
    stroke-width: 8;
    stroke-linecap: round;
    stroke-dasharray: 314;
    stroke-dashoffset: 314;
    transition: stroke-dashoffset 0.5s ease;
}

.progress-content {
    position: absolute;
    text-align: center;
}

.progress-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.progress-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Status Section */
.status-section {
    display: flex;
    justify-content: space-around;
    margin-bottom: 3rem;
}

.streak-counter,
.xp-counter {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    font-weight: 600;
}

.streak-counter i {
    color: var(--warning-color);
    font-size: 1.2rem;
}

.xp-counter i {
    color: var(--success-color);
    font-size: 1.2rem;
}

/* Exercise Section */
.exercise-section {
    text-align: center;
    margin-bottom: 3rem;
}

.start-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border: none;
    padding: 1.2rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: var(--radius-xl);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin: 0 auto 1rem;
    transition: all 0.3s;
    box-shadow: var(--shadow-md);
}

.start-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.choose-btn {
    background: var(--bg-primary);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-xl);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin: 1rem auto 0;
    transition: all 0.3s;
    box-shadow: var(--shadow-sm);
}

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

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

.exercise-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Pocket Mode Info */
.pocket-mode-info {
    margin-top: 2rem;
}

.info-card {
    background: var(--bg-primary);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    text-align: center;
    border: 2px solid var(--secondary-color);
}

.info-card i {
    color: var(--secondary-color);
    font-size: 2rem;
    margin-bottom: 1rem;
}

.info-card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.info-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Exercise Screen */
.exercise-content {
    text-align: center;
}

.exercise-header {
    display: flex;
    align-items: center;
    margin-bottom: 2rem;
    position: relative;
}

.back-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius-md);
    transition: all 0.2s;
    position: absolute;
    left: 0;
}

.back-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

#exercise-title {
    flex: 1;
    text-align: center;
    margin: 0;
    font-size: 1.5rem;
}

/* Timer */
.exercise-timer {
    margin: 2rem 0;
    display: flex;
    justify-content: center;
}

.timer-circle {
    position: relative;
}

.timer-svg {
    transform: rotate(-90deg);
}

.timer-track {
    fill: none;
    stroke: var(--bg-tertiary);
    stroke-width: 8;
}

.timer-bar {
    fill: none;
    stroke: var(--primary-color);
    stroke-width: 8;
    stroke-linecap: round;
    stroke-dasharray: 565;
    stroke-dashoffset: 0;
    transition: stroke-dashoffset 1s linear;
}

.timer-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

.timer-value {
    display: block;
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
}

.timer-label {
    font-size: 1rem;
    color: var(--text-secondary);
}

/* Exercise Controls */
.exercise-controls {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
}

.pocket-btn {
    background: var(--secondary-color);
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: var(--radius-lg);
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s;
}

.pocket-btn:hover {
    background: #0891B2;
    transform: translateY(-1px);
}

.pocket-btn.active {
    background: var(--warning-color);
}

.control-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 1rem;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    transition: all 0.2s;
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.control-btn:hover {
    background: var(--primary-dark);
    transform: scale(1.05);
}

.control-btn.secondary {
    background: var(--text-secondary);
}

.control-btn.secondary:hover {
    background: var(--text-primary);
}

/* Exercise Instructions */
.exercise-instructions {
    background: var(--bg-primary);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    margin-top: 2rem;
    border-left: 4px solid var(--primary-color);
}

/* Evaluation Screen */
.evaluation-content {
    text-align: center;
    padding: 2rem 0;
}

.evaluation-content h2 {
    color: var(--success-color);
    margin-bottom: 1rem;
}

.evaluation-content p {
    color: var(--text-secondary);
    margin-bottom: 3rem;
    font-size: 1.1rem;
}

.evaluation-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

.eval-btn {
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

.eval-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.eval-btn.tough {
    color: var(--danger-color);
    border-color: var(--danger-color);
}

.eval-btn.tough:hover {
    background: var(--danger-color);
    color: white;
}

.eval-btn.perfect {
    color: var(--success-color);
    border-color: var(--success-color);
}

.eval-btn.perfect:hover {
    background: var(--success-color);
    color: white;
}

.eval-btn.easy {
    color: var(--warning-color);
    border-color: var(--warning-color);
}

.eval-btn.easy:hover {
    background: var(--warning-color);
    color: white;
}

/* Reward Animation */
.reward-section {
    text-align: center;
    margin-top: 2rem;
}

.reward-animation {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--success-color);
    animation: bounceIn 0.6s ease-out;
}

.reward-animation i {
    animation: pulse 1s infinite;
}

/* History Screen */
.history-content {
    max-width: 500px;
    margin: 0 auto;
}

.week-view {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
}

.week-header {
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.week-calendar {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 0.5rem;
}

.day-item {
    aspect-ratio: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    font-size: 0.8rem;
    position: relative;
}

.day-item.completed {
    background: var(--success-color);
    color: white;
}

.day-item.partial {
    background: var(--warning-color);
    color: white;
}

.day-item.today {
    border: 2px solid var(--primary-color);
}

.day-label {
    font-size: 0.7rem;
    opacity: 0.8;
}

.day-count {
    font-weight: 600;
}

/* History Stats */
.history-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

.stat-card {
    background: var(--bg-primary);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    display: block;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Settings Screen */
.settings-content {
    max-width: 500px;
    margin: 0 auto;
}

.setting-group {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
}

.setting-group h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.setting-item {
    margin-bottom: 1rem;
}

.setting-item:last-child {
    margin-bottom: 0;
}

.setting-item label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.setting-item select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: var(--bg-primary);
}

.setting-item input[type="checkbox"] {
    margin-right: 0.5rem;
}

.danger-btn {
    background: var(--danger-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.danger-btn:hover {
    background: #DC2626;
}

/* Modal/Onboarding */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.modal-content {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 2rem;
    max-width: 500px;
    width: 100%;
    box-shadow: var(--shadow-lg);
    animation: modalSlideIn 0.3s ease-out;
}

.onboarding-step {
    text-align: center;
}

.onboarding-step h2 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.onboarding-step p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-size: 1.1rem;
}

.goal-options {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    justify-content: center;
}

.goal-option {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    padding: 1rem 1.5rem;
    border-radius: var(--radius-lg);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.goal-option:hover {
    border-color: var(--primary-color);
    background: var(--bg-primary);
}

.goal-option.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.notification-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.next-btn,
.primary-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

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

.secondary-btn {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 0.75rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.secondary-btn:hover {
    background: var(--bg-tertiary);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

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

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

@keyframes bounceIn {
    0% { transform: scale(0); opacity: 0; }
    60% { transform: scale(1.2); opacity: 1; }
    100% { transform: scale(1); }
}

@keyframes modalSlideIn {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

/* Responsive Design */
@media (max-width: 480px) {
    .main-content {
        padding: 0 0.75rem;
    }
    
    .screen {
        padding: 1rem 0;
    }
    
    .start-btn {
        padding: 1rem 1.5rem;
        font-size: 1rem;
    }
    
    .progress-ring svg,
    .timer-svg {
        width: 150px;
        height: 150px;
    }
    
    .timer-value {
        font-size: 2.5rem;
    }
    
    .evaluation-buttons {
        gap: 0.75rem;
    }
    
    .goal-options {
        flex-direction: column;
        align-items: center;
    }
    
    .goal-option {
        width: 100%;
        max-width: 200px;
    }
    
    .history-stats {
        grid-template-columns: 1fr;
    }
}

/* Exercise Selection Screen */
.exercise-selection-content {
    padding: 2rem 0;
}

.selection-header {
    display: flex;
    align-items: center;
    margin-bottom: 2rem;
    position: relative;
}

.selection-header h2 {
    flex: 1;
    text-align: center;
    margin: 0;
    font-size: 1.5rem;
}

.category-filters {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    overflow-x: auto;
    padding-bottom: 0.5rem;
}

.filter-btn {
    background: var(--bg-primary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-lg);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
    transition: all 0.2s;
    min-width: fit-content;
}

.filter-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.filter-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.exercise-list {
    display: grid;
    gap: 1rem;
}

.exercise-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.exercise-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.exercise-card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.exercise-card-icon {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
}

.exercise-card-icon.stretch {
    background: var(--success-color);
}

.exercise-card-icon.strength {
    background: var(--warning-color);
}

.exercise-card-icon.cardio {
    background: var(--danger-color);
}

.exercise-card-info {
    flex: 1;
}

.exercise-card-name {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.exercise-card-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.exercise-card-level {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.level-indicator {
    display: flex;
    gap: 2px;
}

.level-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--border-color);
}

.level-dot.active {
    background: var(--primary-color);
}

.exercise-card-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 0.5rem;
    line-height: 1.4;
}

/* Exercise Preview Screen */
.preview-content {
    padding: 2rem 0;
    text-align: center;
}

.preview-header {
    display: flex;
    align-items: center;
    margin-bottom: 2rem;
    position: relative;
}

.preview-header h2 {
    flex: 1;
    text-align: center;
    margin: 0;
    font-size: 1.5rem;
}

.preview-info {
    max-width: 400px;
    margin: 0 auto;
}

.preview-icon {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: white;
    margin: 0 auto 1.5rem;
    background: var(--primary-color);
}

.preview-icon.stretch {
    background: var(--success-color);
}

.preview-icon.strength {
    background: var(--warning-color);
}

.preview-icon.cardio {
    background: var(--danger-color);
}

#preview-name {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

#preview-category {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 2rem;
    text-transform: capitalize;
}

.preview-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-item {
    background: var(--bg-primary);
    padding: 1rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.stat-item i {
    color: var(--primary-color);
    font-size: 1.2rem;
}

.stat-item span {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-primary);
}

.preview-description,
.preview-requirements {
    background: var(--bg-primary);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    margin-bottom: 1.5rem;
    text-align: left;
    box-shadow: var(--shadow-sm);
}

.preview-description h4,
.preview-requirements h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.preview-description p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.requirement-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.requirement-tag {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
}

.requirement-tag.equipment {
    background: var(--secondary-color);
    color: white;
}

.requirement-tag.space {
    background: var(--success-color);
    color: white;
}

.requirement-tag.difficulty {
    background: var(--warning-color);
    color: white;
}

.preview-actions {
    margin-top: 2rem;
}

.start-selected-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border: none;
    padding: 1.2rem 2.5rem;
    font-size: 1.2rem;
    font-weight: 600;
    border-radius: var(--radius-xl);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin: 0 auto;
    transition: all 0.3s;
    box-shadow: var(--shadow-md);
}

.start-selected-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

/* Responsive Design for Exercise Selection */
@media (max-width: 480px) {
    .category-filters {
        gap: 0.25rem;
        padding: 0 0.5rem 0.5rem 0;
    }
    
    .filter-btn {
        font-size: 0.8rem;
        padding: 0.6rem 0.8rem;
    }
    
    .exercise-card {
        padding: 1rem;
    }
    
    .exercise-card-header {
        gap: 0.75rem;
    }
    
    .exercise-card-icon {
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }
    
    .exercise-card-name {
        font-size: 1.1rem;
    }
    
    .exercise-card-meta {
        gap: 0.75rem;
        font-size: 0.8rem;
    }
    
    .preview-stats {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }
    
    .stat-item {
        padding: 0.75rem;
    }
    
    .preview-icon {
        width: 80px;
        height: 80px;
        font-size: 2.5rem;
    }
    
    #preview-name {
        font-size: 1.8rem;
    }
    
    .start-selected-btn {
        padding: 1rem 2rem;
        font-size: 1.1rem;
    }
}

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