:root {
    --bg-color: #0a0a0a;
    --wall-color: #1a1a1a;
    --text-color: #e0e0e0;
    --accent-color: #4a9eff;
    --whisper-color: rgba(255, 255, 255, 0.7);
    --shadow-color: rgba(74, 158, 255, 0.3);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

.title {
    font-size: 3rem;
    font-weight: 300;
    letter-spacing: 3px;
    background: linear-gradient(45deg, var(--accent-color), #a4c8ff);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1rem;
    opacity: 0.7;
    letter-spacing: 1px;
}

main {
    flex: 1;
}

.wall-container {
    position: relative;
    width: 100%;
    height: 500px;
    background: var(--wall-color);
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

#whisperWall {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.whispers-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.whisper {
    position: absolute;
    font-size: 14px;
    color: var(--whisper-color);
    text-shadow: 0 0 10px var(--shadow-color);
    white-space: nowrap;
    animation: float 20s linear forwards;
    pointer-events: none;
    font-family: 'Courier New', monospace;
}

@keyframes float {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    to {
        transform: translateX(-100%);
        opacity: 0;
    }
}

.whisper-form {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 30px;
}

#whisperInput {
    width: 100%;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-color);
    padding: 15px;
    border-radius: 5px;
    font-size: 16px;
    resize: none;
    margin-bottom: 15px;
    transition: all 0.3s ease;
}

#whisperInput:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 20px rgba(74, 158, 255, 0.2);
}

.form-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.char-count {
    font-size: 14px;
    opacity: 0.6;
}

.whisper-button {
    background: linear-gradient(45deg, var(--accent-color), #6ab7ff);
    color: white;
    border: none;
    padding: 10px 30px;
    border-radius: 25px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(74, 158, 255, 0.3);
}

.whisper-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(74, 158, 255, 0.4);
}

.whisper-button:active {
    transform: translateY(0);
}

.language-selector {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 30px;
}

.lang-btn {
    background: transparent;
    color: var(--text-color);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 8px 20px;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.lang-btn.active {
    background: var(--accent-color);
    border-color: var(--accent-color);
    color: white;
}

.lang-btn:hover:not(.active) {
    border-color: var(--accent-color);
    color: var(--accent-color);
}

footer {
    text-align: center;
    padding: 20px 0;
    opacity: 0.5;
    font-size: 14px;
}

/* レスポンシブデザイン */
@media (max-width: 768px) {
    .title {
        font-size: 2rem;
    }
    
    .wall-container {
        height: 400px;
    }
    
    .whisper {
        font-size: 12px;
    }
}