/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

body {
    /* 默认深色底 */
    background-color: #111;
    color: #fff;
    line-height: 1.6;
}

/* Colors based on BMW China & Luxury Theme */
:root {
    --bmw-blue: #1c69d4;
    --bmw-blue-hover: #0052b3;
    --dark-grey: #1a1a1a;
    --light-grey: #e6e6e6;
    --white: #ffffff;
    --glass-bg: rgba(20, 20, 20, 0.65);
    --glass-border: rgba(255, 255, 255, 0.15);
}

/* ==================================================
   Page 1: Login Page
   ================================================== */
.login-page {
    /* 宝马背景图配合暗色渐变遮罩 */
    background: url('images/bg1.jpg') no-repeat center center fixed;
    background-size: cover;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    transition: background-image 0.6s ease-in-out; /* 增加背景切换时的平滑过渡动画 */
}

.login-container {
    /* 高级毛玻璃效果 */
    background: var(--glass-bg);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    padding: 50px 40px;
    border-radius: 12px;
    width: 90%;
    max-width: 500px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
    border: 1px solid var(--glass-border);
    text-align: center;
}

.logo-container .logo {
    width: 80px;
    height: auto;
    margin-bottom: 20px;
    filter: drop-shadow(0 0 10px rgba(255,255,255,0.2));
}

.login-container h1 {
    font-size: 26px;
    color: var(--white);
    margin-bottom: 8px;
    font-weight: 300;
    letter-spacing: 1px;
}

.login-container .subtitle {
    font-size: 14px;
    color: #aaa;
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 25px;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 500;
    color: #ddd;
    letter-spacing: 0.5px;
}

.form-group input {
    width: 100%;
    padding: 15px 16px;
    font-size: 16px;
    background: rgba(0, 0, 0, 0.4);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: var(--white);
    border-radius: 6px;
    outline: none;
    transition: all 0.3s ease;
}

.form-group input::placeholder {
    color: #888;
}

.form-group input:focus {
    border-color: var(--bmw-blue);
    background: rgba(0, 0, 0, 0.6);
    box-shadow: 0 0 0 2px rgba(28, 105, 212, 0.3);
}

.btn-primary {
    width: 100%;
    padding: 16px;
    background-color: var(--bmw-blue);
    color: var(--white);
    border: none;
    border-radius: 6px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 15px;
    letter-spacing: 2px;
}

.btn-primary:hover {
    background-color: var(--bmw-blue-hover);
    box-shadow: 0 5px 15px rgba(28, 105, 212, 0.4);
}

/* ==================================================
   Page 2: Catalog Page
   ================================================== */
.catalog-page {
    /* 降低暗色遮罩的透明度，透出更多背景图的原始色彩，或者改为轻微的深蓝/灰色渐变 */
    background: linear-gradient(rgba(20, 30, 45, 0.6), rgba(10, 15, 25, 0.8)), url('images/bg4.jpg') no-repeat center center fixed;
    background-size: cover;
    min-height: 100vh;
}

.header {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-logo {
    width: 50px;
    height: auto;
}

.header-title {
    font-size: 20px;
    font-weight: 300;
    color: var(--white);
    letter-spacing: 1px;
}

.logout-link {
    color: #aaa;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

.logout-link:hover {
    color: var(--white);
}

.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 50px 30px;
}

.welcome-section {
    margin-bottom: 50px;
    text-align: center;
}

.welcome-section h2 {
    font-size: 32px;
    color: var(--white);
    margin-bottom: 12px;
    font-weight: 300;
    letter-spacing: 2px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.5); /* 增加文字阴影确保在亮背景上可见 */
}

.welcome-section p {
    font-size: 16px;
    color: #e0e0e0;
    letter-spacing: 1px;
    text-shadow: 0 1px 3px rgba(0,0,0,0.5);
}

/* Grid Container */
.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 30px;
}

.card {
    height: 320px;
    border-radius: 12px;
    overflow: hidden;
    position: relative;
    background-size: cover;
    background-position: center;
    color: var(--white);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275); /* 更高级的动画曲线 */
    cursor: pointer;
    border: 1px solid rgba(255,255,255,0.1);
    box-shadow: 0 10px 20px rgba(0,0,0,0.3);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.5);
    border-color: rgba(255,255,255,0.3);
}

.card::before {
    /* 卡片内部渐变遮罩，确保文字无论在什么背景图上都清晰 */
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.95) 0%, rgba(0,0,0,0.4) 60%, transparent 100%);
    z-index: 1;
}

.card-content {
    padding: 30px;
    width: 100%;
    position: relative;
    z-index: 2;
}

.card-content h3 {
    font-size: 48px;
    font-weight: 100;
    margin-bottom: 5px;
    color: rgba(255,255,255,0.6);
    font-family: 'Times New Roman', Times, serif; /* 使用衬线体增加数字的高级感 */
}

.card-content h4 {
    font-size: 22px;
    margin-bottom: 10px;
    font-weight: 500;
    letter-spacing: 1px;
}

.card-content p {
    font-size: 14px;
    color: #bbb;
    margin-bottom: 25px;
    line-height: 1.6;
}

.btn-secondary {
    padding: 12px 24px;
    background-color: rgba(255,255,255,0.1);
    backdrop-filter: blur(5px);
    -webkit-backdrop-filter: blur(5px);
    color: var(--white);
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: 6px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
    letter-spacing: 1px;
}

.card:hover .btn-secondary {
    background-color: var(--white);
    color: var(--dark-grey);
    border-color: var(--white);
}

/* 适配 11 到 12 英寸平板设备 */
@media screen and (max-width: 1024px) {
    .grid-container {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    .main-content {
        padding: 40px 20px;
    }
}

@media screen and (max-width: 768px) {
    .grid-container {
        grid-template-columns: 1fr;
    }
    .welcome-section h2 {
        font-size: 26px;
    }
}