:root {
    --bg-primary: #f3f4f6;
    --card-bg: #ffffff;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --accent-color: #4f46e5;
    --accent-hover: #4338ca;
    --input-bg: #f9fafb;
    --input-border: #e5e7eb;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --gradient-start: #667eea;
    --gradient-end: #764ba2;
}

.dark {
    --bg-primary: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --accent-color: #818cf8;
    --accent-hover: #6366f1;
    --input-bg: #334155;
    --input-border: #475569;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --gradient-start: #f59e0b;
    --gradient-end: #ef4444;
}


* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: system-ui, sans-serif;
}

body {
    min-height: 100vh;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.3s ease;
    padding: 20px;
}

.card {
    background: var(--card-bg);
    padding: 32px 24px;
    margin: 0 auto;
    width: 380px;
    max-width: 90%;
    border-radius: 20px;
    box-shadow: 0 20px 40px var(--shadow-color);
    text-align: center;
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
}

h2 {
    margin-bottom: 24px;
    margin-right: 10px;
    color: var(--text-primary);
    font-size: 28px;
    font-weight: 700;
    letter-spacing: 0.5px;
    position: relative;
    display: inline-block;
}

h2::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    border-radius: 2px;
}

.inputs {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 6px;
    margin-bottom: 28px;
    flex-wrap: wrap;
}

.inputs input {
    width: clamp(56px, 18vw, 70px);
    padding: 12px;
    font-size: 18px;
    text-align: center;
    border: 2px solid var(--input-border);
    border-radius: 12px;
    background: var(--input-bg);
    color: var(--text-primary);
    font-weight: 600;
    transition: all 0.2s ease;
}

.inputs input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.inputs span {
    font-size: 24px;
    font-weight: bold;
    color: var(--accent-color);
    margin: 0 2px;
}

.display {
    font-size: clamp(28px, 10vw, 48px);
    font-weight: 800;
    margin-bottom: 32px;
    color: var(--text-primary);
    font-family: 'Courier New', monospace;
    letter-spacing: clamp(0.5px, 1vw, 2px);
    padding: 16px;
    background: var(--input-bg);
    border-radius: 16px;
    border: 2px solid var(--input-border);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.buttons {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 20px;
}

.controls {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 8px;
}

.controls button {
    min-width: 90px;
}

button {
    flex: 1;
    padding: 14px;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.2s ease;
    letter-spacing: 0.5px;
}

.start {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
}

.start:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(79, 70, 229, 0.3);
}

.pause {
    background: var(--accent-color);
    color: white;
}

.pause:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
}

.reset {
    background: var(--input-bg);
    color: var(--text-primary);
    border: 2px solid var(--input-border);
}

.reset:hover {
    background: var(--input-border);
    transform: translateY(-2px);
}

.status {
    margin-top: 16px;
    font-size: 15px;
    color: var(--text-secondary);
    font-weight: 500;
    min-height: 22px;
}

.theme-toggle {
    position: absolute;
    top: 30px;
    right: 5px;
    background: transparent;
    border: none;
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    transform: rotate(30deg);
    border: 2px solid var(--input-border);
}

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

.timer-complete {
    animation: pulse 1s infinite;
    color: #ef4444;
}

@media (max-width: 480px) {
    .card {
        padding: 24px 16px;
    }
    
    .display {
        font-size: 36px;
        padding: 12px;
    }
    
    .inputs input {
        width: 60px;
        padding: 10px;
        font-size: 16px;
    }
    
    button {
        padding: 12px;
        font-size: 15px;
    }
}

@media (max-width: 360px) {
    .card {
        margin: 0 auto;
    }
    h2 {
        font-size: 22px;
    }

    .inputs span {
        font-size: 20px;
    }

    .controls {
        gap: 6px;
    }
}