:root {
    --color-primary: #9146ff;
    --color-primary-light: #a970ff;
    --color-primary-dark: #772ce8;
    
    --color-bg-dark: #0e0e10;
    --color-bg-mid: #18181b;
    --color-bg-light: #1f1f23;

    --color-font-base: #efeff1;
    --color-font-alt: #adadb8;
    --color-border: #444447;

    --main-radius: 8px;
    --font-family-base: 'Noto Sans TC', sans-serif;
}

body {
    font-family: var(--font-family-base);
    background-color: var(--color-bg-dark);
    color: var(--color-font-base);
    margin: 0;
    padding: 40px 20px; /* 增加上下 padding */
}

#container {
    max-width: 720px;
    margin: 0 auto;
    background-color: var(--color-bg-mid);
    padding: 32px;
    border-radius: var(--main-radius);
    border: 1px solid var(--color-border);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

.banner {
    width: 100%;
    height: 180px;
    border-radius: var(--main-radius);
    margin-bottom: 24px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
    background-size: contain; /* 確保圖片完整顯示不裁切 */
    background-position: center; /* 圖片置中 */
    background-repeat: no-repeat; /* 防止圖片重複 */
}

h1 {
    text-align: center;
    font-weight: 700;
    color: var(--color-font-base);
    margin-top: 0;
    margin-bottom: 24px;
}

.streamer-name {
    color: var(--color-primary-light);
}

.twitch-player-container {
    position: relative;
    width: 100%;
    padding-top: 56.25%; /* 16:9 Aspect Ratio */
    margin-bottom: 24px;
    border-radius: var(--main-radius);
    overflow: hidden; /* 確保 iframe 圓角 */
}

.twitch-player-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--color-font-alt);
}

input[type="text"],
input[type="number"],
textarea,
select {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--color-border);
    border-radius: var(--main-radius);
    background-color: var(--color-bg-light);
    color: var(--color-font-base);
    font-size: 16px;
    box-sizing: border-box;
    transition: border-color 0.3s, box-shadow 0.3s;
}

input[type="text"]:focus,
input[type="number"]:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--color-primary-light);
    box-shadow: 0 0 0 3px rgba(145, 70, 255, 0.3);
}

textarea {
    resize: vertical;
    min-height: 80px;
}

small {
    display: block;
    text-align: right;
    color: var(--color-font-alt);
    margin-top: 6px;
    font-size: 12px;
}

select {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%23adadb8' viewBox='0 0 16 16'%3E%3Cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 16px;
    padding-right: 40px; /* 留出空間給箭頭 */
}

button {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary));
    color: var(--color-font-base);
    border: none;
    border-radius: var(--main-radius);
    font-size: 18px;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    margin-top: 10px;
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

button:active {
    transform: translateY(0);
    box-shadow: none;
}

.error-container {
    text-align: center;
    padding: 40px 20px;
}

.error-message {
    font-size: 1.2rem;
    color: var(--color-font-alt);
    margin-bottom: 30px;
}

.back-link {
    display: inline-block;
    padding: 10px 20px;
    background-color: var(--color-primary);
    color: var(--color-font-base);
    text-decoration: none;
    border-radius: var(--main-radius);
    transition: background-color 0.3s;
}

.back-link:hover {
    background-color: var(--color-primary-dark);
}

@media (max-width: 768px) {
    body {
        padding: 20px 10px;
    }
    #container {
        padding: 20px;
    }
    .banner {
        height: 140px;
    }
}