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

:root {
    --bg-primary: #0d0d0d;
    --bg-secondary: #161616;
    --bg-tertiary: #1f1f1f;
    --bg-card: #1a1a1a;
    --bg-card-hover: #252525;
    --text-primary: #f5f5f5;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    --accent-primary: #00d4aa;
    --accent-secondary: #00b894;
    --accent-gradient: linear-gradient(135deg, #00d4aa 0%, #00b894 100%);
    --accent-glow: rgba(0, 212, 170, 0.3);
    --border-color: #2a2a2a;
    --border-light: #333333;
    --shadow-soft: 0 4px 20px rgba(0, 0, 0, 0.4);
    --shadow-strong: 0 8px 40px rgba(0, 0, 0, 0.6);
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

[data-theme="light"] {
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e9ecef;
    --bg-card: #ffffff;
    --bg-card-hover: #f8f9fa;
    --text-primary: #1a1a1a;
    --text-secondary: #495057;
    --text-muted: #6c757d;
    --accent-primary: #00a885;
    --accent-secondary: #008f6f;
    --accent-glow: rgba(0, 168, 133, 0.2);
    --border-color: #dee2e6;
    --border-light: #e9ecef;
    --shadow-soft: 0 4px 20px rgba(0, 0, 0, 0.08);
    --shadow-strong: 0 8px 40px rgba(0, 0, 0, 0.12);
}

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Playfair+Display:wght@400;500;600;700&display=swap');

body {
    font-family: var(--font-body);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: var(--transition-smooth);
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    text-align: center;
    padding: 3rem 2rem;
    margin-bottom: 2rem;
    position: relative;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 150px;
    height: 150px;
    background: var(--accent-gradient);
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.3;
    z-index: -1;
}

.header-content {
    position: relative;
    z-index: 1;
}

header h1 {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    letter-spacing: -0.02em;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

header p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-weight: 300;
    max-width: 500px;
    margin: 0 auto;
}

.theme-toggle {
    position: fixed;
    top: 1.5rem;
    right: 1.5rem;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: var(--transition-smooth);
    z-index: 1000;
    box-shadow: var(--shadow-soft);
}

.theme-toggle:hover {
    transform: scale(1.1);
    border-color: var(--accent-primary);
    box-shadow: 0 0 20px var(--accent-glow);
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
    position: absolute;
    transition: var(--transition-smooth);
}

[data-theme="light"] .theme-toggle .icon-sun,
[data-theme="light"] .theme-toggle .icon-moon {
    display: none;
}

[data-theme="light"] .theme-toggle .icon-moon {
    display: block;
}

[data-theme="light"] .theme-toggle .icon-sun {
    display: none;
}

:not([data-theme="light"]) .theme-toggle .icon-moon {
    display: none;
}

:not([data-theme="light"]) .theme-toggle .icon-sun {
    display: block;
}

form {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow-soft);
    border: 1px solid var(--border-color);
    margin-bottom: 2rem;
    transition: var(--transition-smooth);
}

form:hover {
    border-color: var(--border-light);
    box-shadow: var(--shadow-strong);
}

.form-header {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.form-header h2 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.form-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.form-group {
    margin-bottom: 1.75rem;
    position: relative;
}

.form-group label {
    display: block;
    margin-bottom: 0.6rem;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.form-group label::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -4px;
    width: 30px;
    height: 2px;
    background: var(--accent-gradient);
    border-radius: 2px;
    transition: width 0.3s ease;
}

.form-group:hover label::after {
    width: 50px;
}

.form-group select,
.form-group input {
    width: 100%;
    padding: 1rem 1.25rem;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    font-family: var(--font-body);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    transition: var(--transition-smooth);
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%23a0a0a0' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    background-size: 1.2rem;
    cursor: pointer;
}

.form-group select:focus,
.form-group input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px var(--accent-glow);
    background-color: var(--bg-secondary);
}

.form-group select:hover,
.form-group input:hover {
    border-color: var(--border-light);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

@media (max-width: 600px) {
    .form-row {
        grid-template-columns: 1fr;
    }
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    width: 100%;
    padding: 1.1rem 2rem;
    background: var(--accent-gradient);
    color: #0d0d0d;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    font-family: var(--font-body);
    cursor: pointer;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s ease;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--accent-glow);
}

.btn:hover::before {
    left: 100%;
}

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

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

.routine-result {
    background: var(--bg-card);
    border-radius: 16px;
    box-shadow: var(--shadow-soft);
    border: 1px solid var(--border-color);
    padding: 0;
    overflow: hidden;
    animation: slideUp 0.5s ease-out;
}

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

.result-header {
    padding: 2rem 2rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    background: linear-gradient(180deg, var(--bg-tertiary) 0%, var(--bg-card) 100%);
}

.result-header h2 {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.result-meta {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.result-meta span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.result-meta .badge {
    background: var(--accent-gradient);
    color: #0d0d0d;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.exercise-category {
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition-smooth);
}

.exercise-category:last-child {
    border-bottom: none;
}

.exercise-category:hover {
    background: var(--bg-card-hover);
}

.category-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1.25rem;
}

.category-icon {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
}

.category-icon.warmup {
    background: rgba(255, 193, 7, 0.15);
    color: #ffc107;
}

.category-icon.main {
    background: var(--accent-glow);
    color: var(--accent-primary);
}

.category-icon.cooldown {
    background: rgba(156, 136, 255, 0.15);
    color: #9c88ff;
}

.category-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: 0.02em;
}

.exercise-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.exercise-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.25rem;
    background: var(--bg-tertiary);
    border-radius: 10px;
    transition: var(--transition-smooth);
    border: 1px solid transparent;
}

.exercise-item:hover {
    border-color: var(--border-color);
    transform: translateX(4px);
    background: var(--bg-secondary);
}

.exercise-details {
    flex: 1;
}

.exercise-name {
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.exercise-desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.exercise-time {
    font-weight: 600;
    color: var(--accent-primary);
    font-size: 0.9rem;
    padding: 0.4rem 0.8rem;
    background: var(--accent-glow);
    border-radius: 6px;
    white-space: nowrap;
}

.result-actions {
    padding: 1.5rem 2rem;
    display: flex;
    gap: 1rem;
    background: var(--bg-tertiary);
    border-top: 1px solid var(--border-color);
}

.result-actions .btn {
    flex: 1;
}

.tips {
    padding: 1.5rem 2rem;
    background: linear-gradient(135deg, rgba(0, 212, 170, 0.08) 0%, rgba(0, 184, 148, 0.08) 100%);
    border-top: 1px solid var(--border-color);
}

.tips h4 {
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--accent-primary);
    margin-bottom: 0.75rem;
}

.tips p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.7;
}

footer {
    text-align: center;
    margin-top: auto;
    padding: 2rem;
    color: var(--text-muted);
    font-size: 0.85rem;
}

.hidden {
    display: none;
}

/* Animations for form elements */
.form-group {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.5s ease forwards;
}

.form-group:nth-child(1) { animation-delay: 0.1s; }
.form-group:nth-child(2) { animation-delay: 0.2s; }
.form-group:nth-child(3) { animation-delay: 0.3s; }
.form-group:nth-child(4) { animation-delay: 0.4s; }

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

.btn {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.5s ease 0.5s forwards;
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-light);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    header h1 {
        font-size: 2.25rem;
    }
    
    header p {
        font-size: 1rem;
    }
    
    form {
        padding: 1.5rem;
    }
    
    .exercise-category {
        padding: 1.25rem 1.5rem;
    }
    
    .exercise-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    
    .exercise-time {
        align-self: flex-end;
    }
    
    .result-actions {
        flex-direction: column;
    }
}