:root {
    /* Primary Colors */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #dbeafe;
    --primary-hover: #1d4ed8;
    --primary-shadow: rgb(37 99 235 / 25%);
    
    /* Semantic Colors */
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;
    --accent: #36cfc9;
    
    /* Surface Colors */
    --surface: #ffffff;
    --surface-muted: #f4f6fb;
    --surface-elevated: #ffffff;
    --background: #f8fafc;
    --secondary-bg: #e2e8f0;
    
    /* Border Colors */
    --border: #e2e8f0;
    --border-light: #f1f5f9;
    --border-dark: #cbd5e1;
    
    /* Text Colors */
    --text-main: #0f172a;
    --text-muted: #64748b;
    --text-light: #94a3b8;
    --text-inverse: #ffffff;
    
    /* Shadow System */
    --shadow-soft: 0 20px 45px rgba(15, 23, 42, 0.08);
    --shadow-sm: 0 1px 2px rgb(15 23 42 / 0.08);
    --shadow-md: 0 4px 12px rgb(15 23 42 / 0.08);
    --shadow-lg: 0 12px 24px rgb(15 23 42 / 0.12);
    --shadow-xl: 0 20px 25px rgb(15 23 42 / 0.1);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.75rem;
    --radius-lg: 1.5rem;
    --radius-xl: 2rem;
    --radius-full: 9999px;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    
    /* Legacy Variables */
    --primary-color: var(--primary);
    --primary-color-light: var(--primary-light);
    --surface-color: var(--surface);
    --light-bg: var(--background);
    --border-color: var(--border);
    --text-primary: var(--text-main);
    --text-secondary: var(--text-muted);
    --secondary-color: var(--text-muted);
    --success-color: var(--success);
    --info-color: var(--info);
    --warning-color: var(--warning);
    --danger-color: var(--danger);
    --dark-text: var(--text-main);
    --border-radius: var(--radius-lg);
    --shadow: var(--shadow-md);
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.stopwatch-page {
    padding-bottom: 2rem;
}

.stopwatch-intro {
    margin-bottom: 2rem;
}

.stopwatch-title {
    font-size: clamp(2rem, 5vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--dark-text);
}

.stopwatch-subtitle {
    font-size: clamp(1rem, 2vw, 1.125rem);
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
    max-width: 700px;
    line-height: 1.6;
}

.stopwatch-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: flex-start;
    list-style: none;
    padding: 0;
    margin: 1rem 0 0;
}

.meta-chip {
    background: var(--light-bg);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 500;
    border: 1px solid var(--border-color);
    color: var(--dark-text);
}

.stopwatch-main {
    margin-bottom: 2rem;
}

.stopwatch-card-wrapper {
    margin: 0 auto;
    padding: 0 1rem;
}

.stopwatch-card {
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    border-radius: 24px;
    box-shadow: 0 20px 60px rgba(15, 23, 42, 0.1), 0 0 0 1px rgba(15, 23, 42, 0.05);
    padding: 0;
    overflow: hidden;
    position: relative;
}

.stopwatch-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--success) 50%, var(--accent) 100%);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 2rem 2rem 1.5rem;
    border-bottom: 1px solid var(--border);
}

.header-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex-shrink: 0;
}

.card-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--dark-text);
    margin: 0 0 0.25rem;
}

.card-subtitle {
    font-size: 0.875rem;
    color: var(--secondary-color);
    margin: 0;
}

.stopwatch-display-container {
    padding: 3rem 2rem;
    background: linear-gradient(180deg, rgba(37, 99, 235, 0.02) 0%, transparent 100%);
    position: relative;
}

.display-wrapper {
    position: relative;
    z-index: 1;
}

.time-display {
    font-size: clamp(3.5rem, 10vw, 6rem);
    font-weight: 200;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Courier New', monospace;
    color: var(--dark-text);
    margin-bottom: 1rem;
    line-height: 1.1;
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 0.1em;
    letter-spacing: 0.02em;
    transition: all 0.3s ease;
}

.time-display.running {
    color: var(--success);
    text-shadow: 0 0 20px rgba(16, 185, 129, 0.2);
}

.time-minutes,
.time-seconds {
    font-size: 1.2em;
    font-weight: 300;
}

.time-centiseconds {
    font-size: 0.5em;
    font-weight: 400;
    opacity: 0.8;
    margin-left: 0.1em;
}

.time-separator {
    font-size: 0.7em;
    opacity: 0.6;
    font-weight: 300;
}

.display-label {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: var(--secondary-color);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

.display-label svg {
    width: 16px;
    height: 16px;
    opacity: 0.7;
}

.control-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 2rem 2.5rem;
    flex-wrap: wrap;
}

.control-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 1.125rem 2.25rem;
    border: none;
    border-radius: 16px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    min-width: 140px;
    position: relative;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.control-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s;
}

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

.control-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
}

.control-btn:not(:disabled):hover {
    transform: translateY(-3px);
}

.control-btn:not(:disabled):active {
    transform: translateY(-1px);
}

.btn-icon {
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-text {
    font-weight: 600;
    letter-spacing: 0.3px;
}

.control-btn-primary {
    background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
    color: white;
    box-shadow: 0 8px 24px rgba(16, 185, 129, 0.35);
}

.control-btn-primary:hover:not(:disabled) {
    box-shadow: 0 12px 32px rgba(16, 185, 129, 0.45);
    background: linear-gradient(135deg, #059669 0%, var(--success) 100%);
}

.control-btn-primary.stop {
    background: linear-gradient(135deg, var(--danger) 0%, #dc2626 100%);
    box-shadow: 0 8px 24px rgba(239, 68, 68, 0.35);
}

.control-btn-primary.stop:hover:not(:disabled) {
    box-shadow: 0 12px 32px rgba(239, 68, 68, 0.45);
    background: linear-gradient(135deg, #dc2626 0%, var(--danger) 100%);
}

.control-btn-secondary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: 0 8px 24px var(--primary-shadow);
}

.control-btn-secondary:hover:not(:disabled) {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
    box-shadow: 0 12px 32px rgba(37, 99, 235, 0.4);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1.25rem;
    margin: 0 2rem 2.5rem;
}

.stat-card {
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    padding: 1.75rem 1.5rem;
    border-radius: 16px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(15, 23, 42, 0.08);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid rgba(226, 232, 240, 0.8);
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary);
    opacity: 0;
    transition: opacity 0.3s;
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(15, 23, 42, 0.12);
    border-color: rgba(37, 99, 235, 0.3);
}

.stat-card:hover::before {
    opacity: 1;
}

.stat-card-fastest::before {
    background: var(--success);
}

.stat-card-slowest::before {
    background: var(--danger);
}

.stat-card-average::before {
    background: var(--accent);
}

.stat-icon {
    width: 40px;
    height: 40px;
    margin: 0 auto 1rem;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--primary-light) 0%, rgba(37, 99, 235, 0.1) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
}

.stat-card-fastest .stat-icon {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.1) 0%, rgba(16, 185, 129, 0.05) 100%);
    color: var(--success);
}

.stat-card-slowest .stat-icon {
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.1) 0%, rgba(239, 68, 68, 0.05) 100%);
    color: var(--danger);
}

.stat-card-average .stat-icon {
    background: linear-gradient(135deg, rgba(54, 207, 201, 0.1) 0%, rgba(54, 207, 201, 0.05) 100%);
    color: var(--accent);
}

.stat-value {
    font-size: clamp(1.75rem, 4vw, 2.25rem);
    font-weight: 700;
    color: var(--dark-text);
    margin-bottom: 0.75rem;
    font-family: 'SF Mono', Monaco, monospace;
    line-height: 1.2;
}

.stat-card-fastest .stat-value {
    color: var(--success);
}

.stat-card-slowest .stat-value {
    color: var(--danger);
}

.stat-card-average .stat-value {
    color: var(--accent);
}

.stat-label {
    color: var(--secondary-color);
    font-weight: 500;
    font-size: 0.8125rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.tooltip {
    position: relative;
    display: inline-block;
}

.tooltip-trigger {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--info-color);
    color: white;
    border: none;
    font-size: 0.75rem;
    font-weight: 600;
    cursor: help;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    padding: 0;
    line-height: 1;
    font-family: inherit;
}

.tooltip-trigger:hover {
    background: var(--primary-hover);
    transform: scale(1.1);
}

.tooltiptext {
    visibility: hidden;
    width: 200px;
    background-color: var(--dark-text);
    color: white;
    text-align: center;
    border-radius: 8px;
    padding: 0.75rem;
    position: absolute;
    z-index: 1000;
    bottom: 125%;
    left: 50%;
    margin-left: -100px;
    opacity: 0;
    transition: opacity 0.3s;
    font-size: 0.8125rem;
    font-weight: 400;
    line-height: 1.4;
    box-shadow: var(--shadow-lg);
}

.tooltiptext::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 50%;
    margin-left: -5px;
    border-width: 5px;
    border-style: solid;
    border-color: var(--dark-text) transparent transparent transparent;
}

.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}

.laps-container {
    margin: 0;
    padding: 2rem;
    background: linear-gradient(180deg, rgba(248, 250, 252, 0.5) 0%, transparent 100%);
    border-top: 1px solid var(--border);
}

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

.laps-header-left {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.laps-title {
    font-size: 1.375rem;
    font-weight: 700;
    color: var(--dark-text);
    margin: 0;
}

.laps-count {
    font-size: 0.875rem;
    color: var(--secondary-color);
    font-weight: 500;
}

.copy-btn {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    padding: 0.75rem 1.25rem;
    background: white;
    border: 2px solid var(--border);
    border-radius: 12px;
    color: var(--dark-text);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.copy-btn:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
    transform: translateY(-2px);
}

.laps-list {
    max-height: 400px;
    overflow-y: auto;
    padding-right: 0.5rem;
}

.lap-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    margin: 0.5rem 0;
    background: var(--light-bg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border-left: 4px solid transparent;
}

.lap-item:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-md);
}

.lap-item.fastest {
    border-left-color: var(--success);
    background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
}

.lap-item.slowest {
    border-left-color: var(--danger);
    background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
}

.lap-number {
    font-weight: 600;
    color: var(--primary);
    min-width: 60px;
    font-size: 0.875rem;
}

.lap-time {
    font-family: 'SF Mono', Monaco, monospace;
    font-weight: 500;
    color: var(--dark-text);
    font-size: 1rem;
}

.lap-difference {
    font-size: 0.875rem;
    color: var(--secondary-color);
    font-weight: 500;
    margin-left: 1rem;
}

.share-container {
    margin: 0;
    padding: 2rem;
    background: linear-gradient(180deg, rgba(248, 250, 252, 0.5) 0%, transparent 100%);
    border-top: 1px solid var(--border);
}

.share-header {
    margin-bottom: 1.25rem;
}

.share-title {
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--dark-text);
    margin: 0;
    text-align: center;
}

.share-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.share-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition);
    color: white;
}

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

.share-x {
    background: #000000;
}

.share-x:hover {
    background: #1a1a1a;
}

.share-facebook {
    background: #1877f2;
}

.share-facebook:hover {
    background: #166fe5;
}

.share-linkedin {
    background: #0a66c2;
}

.share-linkedin:hover {
    background: #095eaa;
}

.share-reddit {
    background: #ff4500;
}

.share-reddit:hover {
    background: #e63e00;
}

.share-telegram {
    background: #0088cc;
}

.share-telegram:hover {
    background: #0077b5;
}

.share-whatsapp {
    background: #25d366;
}

.share-whatsapp:hover {
    background: #20ba5a;
}

/* Custom Scrollbar */
.laps-list::-webkit-scrollbar {
    width: 8px;
}

.laps-list::-webkit-scrollbar-track {
    background: var(--light-bg);
    border-radius: 4px;
}

.laps-list::-webkit-scrollbar-thumb {
    background: var(--border-dark);
    border-radius: 4px;
}

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

/* Educational Content Styles */
.angle-seo-section {
    margin-top: clamp(3rem, 5vw, 4rem);
}

.angle-card {
    margin-top: clamp(2.5rem, 4vw, 3.5rem);
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: clamp(2rem, 4vw, 2.75rem);
    border: 1px solid rgba(148, 163, 184, 0.25);
    box-shadow: var(--shadow-sm);
}

.angle-education-card h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--dark-text);
    margin-bottom: 1rem;
}

.angle-education-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--dark-text);
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.angle-education-card p {
    color: var(--text-muted);
    line-height: 1.8;
    margin-bottom: 1rem;
}

.angle-education-card a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
}

.angle-education-card a:hover {
    text-decoration: underline;
}

.infographic-timeline {
    margin: 2rem 0;
    padding: 2rem;
    background: var(--light-bg);
    border-radius: 12px;
}

.infographic-conversion-formula {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
    padding: 2rem;
    background: var(--light-bg);
    border-radius: 12px;
}

.infographic-title {
    grid-column: 1 / -1;
    font-size: 1.25rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--dark-text);
}

.formula-box {
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.formula-label {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.formula-content {
    font-size: 1rem;
    font-weight: 600;
    color: var(--dark-text);
    margin-bottom: 0.5rem;
}

.formula-example {
    font-size: 0.875rem;
    color: var(--secondary-color);
}

/* Responsive Design */
@media (max-width: 768px) {
    .stopwatch-card-wrapper {
        padding: 0 0.5rem;
    }
    
    .card-header {
        padding: 1.5rem 1.5rem 1rem;
    }
    
    .stopwatch-display-container {
        padding: 2rem 1.5rem;
    }
    
    .time-display {
        font-size: 3.5rem;
    }
    
    .control-buttons {
        margin: 1.5rem 1.5rem 2rem;
        flex-direction: column;
        align-items: stretch;
    }
    
    .control-btn {
        width: 100%;
        max-width: 100%;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        margin: 0 1.5rem 2rem;
        gap: 1rem;
    }
    
    .laps-container {
        padding: 1.5rem;
    }
    
    .laps-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    .copy-btn {
        width: 100%;
        justify-content: center;
    }
    
    .share-container {
        padding: 1.5rem;
    }
    
    .share-buttons {
        justify-content: center;
    }
    
    .share-btn {
        flex: 1;
        min-width: calc(50% - 0.375rem);
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .card-header {
        padding: 1.25rem 1rem 0.75rem;
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    
    .stopwatch-display-container {
        padding: 1.5rem 1rem;
    }
    
    .time-display {
        font-size: 2.75rem;
    }
    
    .control-buttons {
        margin: 1.25rem 1rem 1.75rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        margin: 0 1rem 1.75rem;
    }
    
    .laps-container,
    .share-container {
        padding: 1.25rem 1rem;
    }
    
    .share-btn {
        min-width: 100%;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease-in;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.02);
    }
}

.pulse {
    animation: pulse 2s infinite;
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !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-width: 0;
}