/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Arial, sans-serif;
}

/* 配色方案 */
:root {
    --primary: #4A90E2;
    --secondary: #6C5CE7;
    --accent: #FF6B6B;
    --light-bg: #F8FAFF;
    --dark-text: #2D3748;
    --gray: #718096;
    --border: #E2E8F0;
}

body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background: linear-gradient(rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0.9)),
                url('https://images.unsplash.com/photo-1583337130417-3346a1be7dee?ixlib=rb-1.2.1&auto=format&fit=crop&w=1950&q=80') center/cover;
}

/* 导航栏样式 */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    padding: 1rem 5%;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s ease;
}

.navbar.hidden {
    transform: translateY(-100%);
    box-shadow: none;
}

.logo-container {
    display: flex;
    align-items: center;
    text-decoration: none;
}

.logo-img {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    margin-right: 10px;
}

.logo-text {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary);
}

.nav-menu {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-item {
    position: relative;
    padding: 1rem 0;
}

.nav-link {
    color: var(--dark-text);
    text-decoration: none;
    transition: color 0.3s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link:hover {
    color: var(--primary);
}

/* 下拉菜单 */
.dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    padding: 1rem;
    min-width: 220px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
}

.nav-item:hover .dropdown {
    opacity: 1;
    visibility: visible;
}

.dropdown-item {
    padding: 0.8rem 1rem;
    border-radius: 6px;
    transition: background 0.3s;
}

.dropdown-item:hover {
    background: var(--light-bg);
}

/* 登录容器 */
.login-container {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding-top: 80px;
}

.login-box {
    background: white;
    border-radius: 20px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    width: 400px;
    overflow: hidden;
}

.login-header {
    background: var(--primary);
    color: white;
    padding: 2rem;
    text-align: center;
}

.login-header h2 {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
}

.login-header p {
    font-size: 1rem;
    opacity: 0.9;
}

.login-form {
    padding: 2rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    color: var(--dark-text);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.form-group input {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary);
}

.form-options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

.remember-me {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.forgot-password {
    color: var(--primary);
    text-decoration: none;
}

.forgot-password:hover {
    text-decoration: underline;
}

.login-button {
    width: 100%;
    padding: 1rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s;
}

.login-button:hover {
    background: var(--secondary);
}

.divider {
    display: flex;
    align-items: center;
    margin: 1.5rem 0;
    color: var(--gray);
    font-size: 0.9rem;
}

.divider::before,
.divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border);
}

.divider::before {
    margin-right: 1rem;
}

.divider::after {
    margin-left: 1rem;
}

.social-login {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.social-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.8rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: white;
    color: var(--dark-text);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s;
}

.social-button:hover {
    background: var(--light-bg);
    border-color: var(--primary);
}

.register-link {
    text-align: center;
    margin-top: 1.5rem;
    font-size: 0.9rem;
}

.register-link a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
}

.register-link a:hover {
    text-decoration: underline;
}

.error-message {
    color: var(--accent);
    font-size: 0.9rem;
    margin-top: 0.5rem;
    display: none;
}