/**
 * ==================== Base Styles ====================
 * CSS Reset, Variables, Typography, Utilities
 * Brand Color: #E3000F (普利司通红)
 */

/* ==================== CSS Reset ==================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-weight: 400;
    line-height: 1.6;
    color: #333333;
    background-color: #ffffff;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

/* ==================== Typography ==================== */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Roboto Condensed', 'Roboto', sans-serif;
    font-weight: 700;
    line-height: 1.2;
    color: #333333;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color 0.3s ease;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

ul, ol {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* ==================== CSS Variables ==================== */
:root {
    --color-brand: #E3000F;
    --color-brand-dark: #B8000C;
    --color-brand-light: #FF1A26;
    --color-dark: #333333;
    --color-gray: #666666;
    --color-gray-light: #999999;
    --color-light: #F5F5F5;
    --color-lighter: #FAFAFA;
    --color-border: #E0E0E0;
    --color-white: #ffffff;
    --color-black: #000000;
    
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    --container-max: 1280px;
    --header-height: 80px;
}

/* ==================== Container ==================== */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 20px;
}

@media (min-width: 640px) {
    .container { padding: 0 24px; }
}

@media (min-width: 1024px) {
    .container { padding: 0 32px; }
}

/* ==================== Utility Classes ==================== */
.text-center { text-align: center; }
.text-brand { color: var(--color-brand); }
.bg-brand { background-color: var(--color-brand); }

.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }

.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; }

/* ==================== Section Headers ==================== */
.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-title {
    font-size: 36px;
    font-weight: 900;
    color: var(--color-dark);
    margin-bottom: 12px;
    text-transform: uppercase;
}

.section-title span { color: var(--color-brand); }

.section-subtitle {
    font-size: 16px;
    color: var(--color-gray);
    max-width: 600px;
    margin: 0 auto;
}

/* ==================== Keyframe Animations ==================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-fadeInUp {
    animation: fadeInUp 0.6s ease forwards;
}

/* ==================== Image Placeholder ==================== */
.product-image-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f5f5f5;
}

/* ==================== Empty State ==================== */
.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 60px 20px;
    color: #666;
}

.empty-state-icon {
    margin-bottom: 16px;
}

/* ==================== Table Responsive ==================== */
.table-responsive {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

/* ==================== Print Styles ==================== */
@media print {
    .top-bar, .main-header, .main-footer,
    .mobile-menu-toggle, .btn {
        display: none !important;
    }
    .main-content { min-height: auto; }
}

/* ==================== Mobile Base ==================== */
@media (max-width: 640px) {
    html { font-size: 14px; }
    .container { padding: 0 16px; }
    h1 { font-size: 1.75rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }
    .section-title { font-size: 24px; }
}

@media (max-width: 480px) {
    html { font-size: 13px; }
    .container { padding: 0 12px; }
    h1 { font-size: 1.5rem; }
    h2 { font-size: 1.3rem; }
    h3 { font-size: 1.15rem; }
    .section-title { font-size: 22px; }
    .section-header { margin-bottom: 32px; }
}

@media (max-width: 360px) {
    html { font-size: 12px; }
    .container { padding: 0 10px; }
    body { overflow-x: hidden; }
    img { max-width: 100%; }
}