/* ========== 全局重置 ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #0f0c29, #302b63, #24243e);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    color: #fff;
}

/* ========== 登录卡片 ========== */
.login-card {
    width: 420px;
    padding: 48px 40px;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.06);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    animation: fadeInUp 0.6s ease-out;
}

.login-card h1 {
    text-align: center;
    font-size: 1.6rem;
    font-weight: 400;
    letter-spacing: 2px;
    margin-bottom: 8px;
    background: linear-gradient(90deg, #667eea, #764ba2, #f093fb);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.login-card .subtitle {
    text-align: center;
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.4);
    letter-spacing: 1px;
    margin-bottom: 36px;
}

/* ========== Tab 切换 ========== */
.tab-group {
    display: flex;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 32px;
}

.tab-btn {
    flex: 1;
    padding: 12px 0;
    background: none;
    border: none;
    color: rgba(255, 255, 255, 0.4);
    font-size: 0.95rem;
    cursor: pointer;
    position: relative;
    transition: color 0.3s;
    letter-spacing: 1px;
}

.tab-btn:hover {
    color: rgba(255, 255, 255, 0.7);
}

.tab-btn.active {
    color: #fff;
    font-weight: 500;
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 20%;
    width: 60%;
    height: 2px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    border-radius: 2px;
}

/* ========== Tab 内容面板 ========== */
.tab-panel {
    display: none;
    animation: fadeIn 0.4s ease;
}

.tab-panel.active {
    display: block;
}

/* ========== 手机号登录表单 ========== */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.5);
    margin-bottom: 8px;
    letter-spacing: 1px;
}

.form-group input {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.05);
    color: #fff;
    font-size: 1rem;
    outline: none;
    transition: border-color 0.3s;
}

.form-group input:focus {
    border-color: rgba(102, 126, 234, 0.6);
}

.form-group input::placeholder {
    color: rgba(255, 255, 255, 0.2);
}

.btn-primary {
    width: 100%;
    padding: 13px;
    border: none;
    border-radius: 10px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: #fff;
    font-size: 1rem;
    font-weight: 500;
    letter-spacing: 2px;
    cursor: pointer;
    transition: opacity 0.3s, transform 0.2s;
    margin-top: 8px;
}

.btn-primary:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.btn-primary:active {
    transform: translateY(0);
}

/* ========== 钉钉登录面板 ========== */
.dingtalk-panel {
    text-align: center;
    padding: 20px 0;
}

.dingtalk-icon {
    width: 72px;
    height: 72px;
    margin: 0 auto 20px;
    border-radius: 18px;
    background: linear-gradient(135deg, #3296fa, #1677ff);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 20px rgba(50, 150, 250, 0.3);
}

.dingtalk-icon svg {
    width: 40px;
    height: 40px;
    fill: #fff;
}

.dingtalk-panel p {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.9rem;
    margin-bottom: 28px;
    line-height: 1.6;
}

.btn-dingtalk {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    padding: 13px;
    border: none;
    border-radius: 10px;
    background: linear-gradient(135deg, #3296fa, #1677ff);
    color: #fff;
    font-size: 1rem;
    font-weight: 500;
    letter-spacing: 2px;
    cursor: pointer;
    transition: opacity 0.3s, transform 0.2s;
    text-decoration: none;
}

.btn-dingtalk:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.btn-dingtalk:active {
    transform: translateY(0);
}

.btn-dingtalk svg {
    width: 20px;
    height: 20px;
    fill: #fff;
}

/* ========== 底部提示 ========== */
.login-footer {
    text-align: center;
    margin-top: 28px;
    font-size: 0.78rem;
    color: rgba(255, 255, 255, 0.25);
    letter-spacing: 1px;
}

/* ========== 动画 ========== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(24px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}