:root {
    color-scheme: light dark;
    font-family: "Noto Sans JP", "Hiragino Kaku Gothic ProN", Arial, sans-serif;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #74ebd5 0%, #acb6e5 100%);
    padding: 24px;
}

.layout {
    width: min(960px, 100%);
    display: flex;
    flex-direction: column;
    gap: 24px;
    align-items: center;
}

.player {
    width: min(680px, 100%);
    background: rgba(255, 255, 255, 0.92);
    border-radius: 18px;
    padding: 28px;
    box-shadow: 0 12px 35px rgba(0, 0, 0, 0.18);
    backdrop-filter: blur(6px);
}

.manager {
    width: min(680px, 100%);
    background: rgba(255, 255, 255, 0.92);
    border-radius: 18px;
    padding: 24px 28px;
    box-shadow: 0 12px 35px rgba(0, 0, 0, 0.18);
    backdrop-filter: blur(6px);
}

h2 {
    margin: 0 0 12px;
    font-size: 1.4rem;
    color: #2c3e50;
    text-align: center;
}

.manager-description {
    margin-bottom: 16px;
}

.upload-form {
    display: grid;
    gap: 12px;
}

.file-input {
    display: none;
}

.file-input-label {
    display: block;
    text-align: center;
    border-radius: 10px;
    padding: 14px 18px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
    background: #3498db;
    color: #ffffff;
}

.file-input-label:hover,
.file-input-label:focus-visible {
    outline: none;
    transform: translateY(-1px);
    background: #2c81be;
    box-shadow: 0 6px 16px rgba(52, 152, 219, 0.4);
}

.upload-button {
    background: #27ae60;
    color: #ffffff;
}

.upload-button:hover,
.upload-button:focus-visible {
    background: #1f8c4d;
}

.file-name {
    padding: 10px;
    border-radius: 10px;
    background: rgba(52, 152, 219, 0.12);
    color: #34495e;
    text-align: center;
}

.message {
    margin: 12px 0 0;
    padding: 12px;
    border-radius: 10px;
    text-align: center;
    font-size: 0.95rem;
}

.message.info {
    background: rgba(52, 152, 219, 0.15);
    color: #2980b9;
}

.message.success {
    background: rgba(39, 174, 96, 0.15);
    color: #27ae60;
}

.message.error {
    background: rgba(231, 76, 60, 0.15);
    color: #e74c3c;
}

.helper-text {
    margin: 10px 0 0;
    text-align: center;
    font-size: 0.9rem;
    color: #556170;
}

h1 {
    margin: 0 0 12px;
    font-size: 1.9rem;
    color: #2c3e50;
    text-align: center;
}

.description {
    margin: 0 0 20px;
    line-height: 1.6;
    color: #34495e;
    text-align: center;
}

button {
    appearance: none;
    border: none;
    border-radius: 10px;
    padding: 12px 18px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
    background: rgba(52, 152, 219, 0.12);
    color: #2c3e50;
}

button:hover,
button:focus-visible {
    outline: none;
    transform: translateY(-1px);
    background: rgba(52, 152, 219, 0.22);
    box-shadow: 0 6px 16px rgba(52, 152, 219, 0.28);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.status {
    margin: 0 0 12px;
    text-align: center;
    color: #2c3e50;
    font-size: 0.95rem;
}

.now-playing {
    margin: 0 0 12px;
    font-size: 1rem;
    color: #2c3e50;
}

.playlist {
    display: grid;
    gap: 12px;
    margin-bottom: 24px;
}

.empty-message {
    margin: 0;
    padding: 18px;
    border-radius: 12px;
    background: rgba(52, 152, 219, 0.12);
    text-align: center;
    color: #556170;
    font-size: 0.95rem;
}

.track-button {
    width: 100%;
    text-align: left;
    background: rgba(52, 152, 219, 0.1);
    color: #34495e;
}

.track-button.active {
    background: #3498db;
    color: #ffffff;
    box-shadow: 0 10px 22px rgba(52, 152, 219, 0.35);
}

audio {
    width: 100%;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.8);
}

@media (prefers-color-scheme: dark) {
    body {
        background: linear-gradient(135deg, #1f1c2c 0%, #928dab 100%);
    }

    .player {
        background: rgba(25, 27, 41, 0.9);
        color: #ecf0f1;
    }

    h1,
    .description,
    .status,
    .now-playing {
        color: rgba(236, 240, 241, 0.9);
    }

    button {
        background: rgba(52, 152, 219, 0.18);
        color: rgba(236, 240, 241, 0.9);
    }

    .manager {
        background: rgba(25, 27, 41, 0.9);
    }

    h2,
    .helper-text,
    .file-name {
        color: rgba(236, 240, 241, 0.9);
    }

    .file-input-label {
        background: #2d89c6;
    }

    .upload-button {
        background: #229954;
    }

    .empty-message {
        background: rgba(52, 152, 219, 0.22);
        color: rgba(236, 240, 241, 0.8);
    }
}