:root {
    --bg: #ffffff;
    --text-main: #000000;
    --text-sub: #666666;
    --border: #eeeeee;
    --input-focus: #000000;
    --btn-bg: #000000;
    --btn-text: #ffffff;
    --error: #ff0000;
    --success: #155724;
    --success-bg: #d4edda;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    background-color: var(--bg);
    color: var(--text-main);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 360px;
    padding: 24px;
}

/* 顶部设计 */
.header {
    text-align: center;
    margin-bottom: 40px;
}

.icon-box {
    margin-bottom: 16px;
}

.icon-box svg {
    width: 40px;
    height: 40px;
    fill: var(--text-main);
}

h1 {
    font-size: 20px;
    font-weight: 600;
    letter-spacing: -0.5px;
    margin-bottom: 8px;
}

.subtitle {
    font-size: 14px;
    color: var(--text-sub);
}

/* 表单部分 */
.form-group {
    margin-bottom: 24px;
}

label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
    color: var(--text-sub);
}

input[type="text"] {
    width: 100%;
    padding: 12px 0;
    font-size: 16px;
    background: transparent;
    border: none;
    border-bottom: 2px solid var(--border);
    border-radius: 0;
    outline: none;
    transition: border-color 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

input[type="text"]:focus {
    border-bottom-color: var(--input-focus);
}

/* Turnstile 居中 */
.turnstile-container {
    display: flex;
    justify-content: center;
    margin: 32px 0;
    min-height: 65px;
}

/* 纯黑按钮 */
.btn-submit {
    width: 100%;
    padding: 14px;
    background-color: var(--btn-bg);
    color: var(--btn-text);
    border: 1px solid var(--btn-bg);
    border-radius: 4px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-submit:hover {
    background-color: transparent;
    color: var(--btn-bg);
}

.btn-submit:active {
    transform: scale(0.98);
}

.btn-submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* 提示消息 */
.message {
    margin-top: 24px;
    font-size: 13px;
    text-align: center;
    min-height: 20px;
    transition: all 0.3s;
    display: none;
}

.message.error {
    color: var(--error);
    display: block;
}

.message.success {
    color: var(--success);
    font-weight: 600;
    display: block;
}

/* 成功页面样式 */
.success-icon {
    font-size: 80px;
    text-align: center;
    margin-bottom: 20px;
    animation: scaleIn 0.5s ease-out;
}

@keyframes scaleIn {
    from {
        transform: scale(0);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.success-message {
    font-size: 18px;
    color: var(--success);
    font-weight: 600;
    text-align: center;
    margin-bottom: 30px;
}

.info-box {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 20px;
    margin: 20px 0;
}

.info-box p {
    margin: 10px 0;
    color: var(--text-main);
    font-size: 14px;
}

.info-box strong {
    color: var(--text-main);
    font-weight: 600;
}

.btn-back {
    display: block;
    width: 100%;
    padding: 14px;
    background-color: var(--btn-bg);
    color: var(--btn-text);
    text-decoration: none;
    border: 1px solid var(--btn-bg);
    border-radius: 4px;
    font-size: 14px;
    font-weight: 500;
    text-align: center;
    transition: all 0.2s;
}

.btn-back:hover {
    background-color: transparent;
    color: var(--btn-bg);
}

.btn-back:active {
    transform: scale(0.98);
}

/* 针对移动端的优化 */
@media (max-width: 480px) {
    .container {
        padding: 16px;
    }
}