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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s ease;
}

/* テーマ */
body.theme-light {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    color: #2c3e50;
}

body.theme-dark {
    background: linear-gradient(135deg, #1e1e1e 0%, #2d2d2d 100%);
    color: #ecf0f1;
}

body.theme-neon {
    background: #0a0a0a;
    color: #00ff00;
}

.container {
    text-align: center;
    padding: 20px;
    width: 100%;
    max-width: 600px;
}

header {
    margin-bottom: 40px;
}

h1 {
    font-size: 2rem;
    margin-bottom: 20px;
    font-weight: 300;
    letter-spacing: 2px;
}

.language-selector {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.lang-btn {
    padding: 8px 20px;
    border: none;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.2);
    color: inherit;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

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

.lang-btn.active {
    background: rgba(255, 255, 255, 0.4);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

/* 時計ウィジェット */
.clock-widget {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 30px;
    padding: 40px;
    margin-bottom: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.theme-dark .clock-widget {
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.theme-neon .clock-widget {
    background: rgba(0, 255, 0, 0.05);
    border: 2px solid #00ff00;
    box-shadow: 0 0 30px #00ff00, inset 0 0 20px rgba(0, 255, 0, 0.1);
}

.time-display {
    font-size: 5rem;
    font-weight: 200;
    font-variant-numeric: tabular-nums;
    letter-spacing: 5px;
    margin-bottom: 20px;
}

.theme-neon .time-display {
    text-shadow: 0 0 20px #00ff00, 0 0 40px #00ff00;
    font-family: 'Courier New', monospace;
}

.separator {
    animation: blink 2s infinite;
    display: inline-block;
    width: 20px;
    text-align: center;
}

@keyframes blink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0.3; }
}

.date-display, .day-display {
    font-size: 1.2rem;
    opacity: 0.8;
    margin: 5px 0;
}

/* 設定 */
.settings {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
    align-items: center;
    margin-bottom: 30px;
}

.settings label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 0.95rem;
}

.settings input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.settings select {
    padding: 5px 10px;
    border-radius: 5px;
    border: 1px solid rgba(255, 255, 255, 0.3);
    background: rgba(255, 255, 255, 0.1);
    color: inherit;
    cursor: pointer;
    font-size: 0.9rem;
}

.theme-dark select {
    background: rgba(0, 0, 0, 0.3);
    border-color: rgba(255, 255, 255, 0.2);
}

.theme-neon select {
    background: #000;
    border-color: #00ff00;
    color: #00ff00;
}

/* フッター */
footer {
    opacity: 0.6;
    font-size: 0.85rem;
}

/* レスポンシブ */
@media (max-width: 600px) {
    h1 {
        font-size: 1.5rem;
    }
    
    .time-display {
        font-size: 3rem;
        letter-spacing: 2px;
    }
    
    .clock-widget {
        padding: 30px 20px;
    }
    
    .settings {
        flex-direction: column;
        gap: 15px;
    }
}