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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    color: #fff;
}

.container {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 30px;
    padding: 40px;
    max-width: 450px;
    width: 100%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.app-header {
    text-align: center;
    margin-bottom: 40px;
}

.app-header h1 {
    font-size: 2.5em;
    font-weight: 700;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1em;
    opacity: 0.9;
    font-weight: 300;
}

.timer-display {
    text-align: center;
    margin-bottom: 40px;
    background: rgba(255, 255, 255, 0.15);
    padding: 30px;
    border-radius: 20px;
    border: 2px solid rgba(255, 255, 255, 0.2);
}

.time {
    font-size: 4em;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-shadow: 2px 2px 8px rgba(0, 0, 0, 0.3);
    margin-bottom: 10px;
}

.status {
    font-size: 1.1em;
    opacity: 0.9;
    font-weight: 300;
}

.preset-buttons {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
    justify-content: center;
}

.preset-btn {
    flex: 1;
    padding: 15px 20px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    border-radius: 15px;
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.preset-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.preset-btn.active {
    background: rgba(255, 255, 255, 0.3);
    border-color: rgba(255, 255, 255, 0.6);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.controls {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
}

.control-btn {
    flex: 1;
    padding: 18px 30px;
    border: none;
    border-radius: 15px;
    font-size: 1.1em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.control-btn.start {
    background: #4ade80;
    color: #fff;
}

.control-btn.start:hover {
    background: #22c55e;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

.control-btn.start.pause {
    background: #f59e0b;
}

.control-btn.start.pause:hover {
    background: #d97706;
}

.control-btn.reset {
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.control-btn.reset:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.control-btn .icon {
    font-size: 1.2em;
}

.tips {
    text-align: center;
    padding: 15px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 15px;
    font-size: 0.95em;
    opacity: 0.9;
    margin-bottom: 20px;
}

.footer {
    text-align: center;
}

.share-btn {
    padding: 12px 30px;
    background: rgba(255, 255, 255, 0.15);
    border: 2px solid rgba(255, 255, 255, 0.3);
    color: #fff;
    border-radius: 12px;
    font-size: 0.95em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 15px;
}

.share-btn:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

.links {
    display: flex;
    gap: 10px;
    justify-content: center;
    align-items: center;
    font-size: 0.9em;
    opacity: 0.8;
}

.links a {
    color: #fff;
    text-decoration: none;
    transition: opacity 0.3s ease;
}

.links a:hover {
    opacity: 1;
    text-decoration: underline;
}

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

.timer-display.running {
    animation: pulse 2s ease-in-out infinite;
}

.timer-display.finished {
    background: rgba(74, 222, 128, 0.3);
    border-color: #4ade80;
}

@media (max-width: 480px) {
    .container {
        padding: 30px 20px;
    }

    .app-header h1 {
        font-size: 2em;
    }

    .time {
        font-size: 3em;
    }

    .preset-buttons {
        gap: 10px;
    }

    .preset-btn {
        padding: 12px 15px;
        font-size: 0.9em;
    }
}