/* 
 * Medio.Cool - 小米官网风格 (Premium Version)
 * 简洁白底、产品为主、无廉价图标
 */

/* ===== 基础变量 ===== */
:root {
    --primary: #ff6700;
    --primary-dark: #ff5000;
    
    --text-primary: #333;
    --text-secondary: #666;
    --text-tertiary: #999;
    
    --bg-white: #fff;
    --bg-gray: #f5f5f5;
    --bg-light: #fafafa;
    
    --shadow: 0 5px 15px rgba(0,0,0,0.08);
    --shadow-hover: 0 10px 30px rgba(0,0,0,0.12);
    
    --radius: 12px;
    --radius-lg: 20px;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset & Base ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    color: var(--text-primary);
    background: var(--bg-white);
    font-size: 14px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
    font-weight: 500;
    color: var(--text-primary);
}

h1 { font-size: 52px; font-weight: 600; letter-spacing: -1px; }
h2 { font-size: 42px; font-weight: 600; letter-spacing: -0.5px; }
h3 { font-size: 24px; }
h4 { font-size: 16px; }

p { color: var(--text-secondary); }

a { text-decoration: none; color: inherit; transition: var(--transition); }

/* ===== Header ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 64px;
    background: rgba(255,255,255,0.98);
    border-bottom: 1px solid rgba(0,0,0,0.05);
    z-index: 1000;
}

.header-inner {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo img { height: 32px; }

.nav { display: flex; gap: 32px; }

.nav a {
    font-size: 14px;
    color: var(--text-primary);
    position: relative;
}

.nav a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
}

.nav a:hover { color: var(--primary); }
.nav a:hover::after { width: 100%; }

.header-btn {
    padding: 8px 20px;
    background: var(--primary);
    color: white;
    border-radius: 6px;
    font-size: 13px;
}

.header-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

/* ===== Hero Section ===== */
.hero {
    padding: 110px 24px 60px;
    background: var(--bg-white);
    min-height: 85vh;
    display: flex;
    align-items: center;
}

.hero-inner {
    max-width: 1400px;
    margin: 0 auto;
    width: 100%;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-text h1 {
    margin-bottom: 20px;
}

.hero-text p {
    font-size: 18px;
    line-height: 1.7;
    margin-bottom: 32px;
    color: var(--text-secondary);
    max-width: 520px;
}

.hero-tags {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 32px;
}

.hero-tags span {
    padding: 6px 14px;
    background: var(--bg-gray);
    border-radius: 4px;
    font-size: 13px;
    color: var(--text-secondary);
}

.hero-btn {
    display: inline-block;
    padding: 12px 32px;
    background: var(--primary);
    color: white;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 500;
}

.hero-btn:hover {
    background: var(--primary-dark);
    box-shadow: 0 8px 24px rgba(255, 103, 0, 0.25);
}

.hero-img {
    position: relative;
}

.hero-img img {
    width: 100%;
    max-width: 640px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-hover);
}

/* ===== Banner Strip ===== */
.banner-strip {
    background: var(--bg-gray);
    padding: 16px 24px;
}

.banner-grid {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.banner-item {
    background: var(--bg-white);
    padding: 20px 24px;
    border-radius: var(--radius);
    transition: var(--transition);
}

.banner-item:hover {
    box-shadow: var(--shadow);
    transform: translateY(-2px);
}

.banner-item h4 {
    margin-bottom: 4px;
    font-weight: 500;
}

.banner-item p {
    font-size: 12px;
    margin: 0;
    color: var(--text-tertiary);
}

/* ===== Section ===== */
.section {
    padding: 80px 24px;
    background: var(--bg-white);
}

.section:nth-child(even) {
    background: var(--bg-gray);
}

.section-inner {
    max-width: 1400px;
    margin: 0 auto;
}

.section-header {
    margin-bottom: 50px;
}

.section-header h2 {
    margin-bottom: 8px;
}

.section-header p {
    font-size: 16px;
}

/* ===== Product Grid - Clean Cards ===== */
.product-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.product-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 48px 32px;
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.product-card::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 3px;
    background: var(--primary);
    opacity: 0;
    transition: var(--transition);
}

.product-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.product-card:hover::after {
    opacity: 1;
}

.product-card h3 {
    margin-bottom: 12px;
}

.product-card p {
    font-size: 13px;
    line-height: 1.7;
}

/* ===== Feature Section ===== */
.feature-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
    padding: 60px 0;
}

.feature-row.reverse .feature-img {
    order: 2;
}

.feature-img img {
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
}

.feature-text h2 {
    margin-bottom: 20px;
}

.feature-text p {
    font-size: 15px;
    margin-bottom: 16px;
    line-height: 1.8;
}

.feature-list {
    list-style: none;
    margin-top: 20px;
}

.feature-list li {
    padding: 10px 0;
    padding-left: 20px;
    position: relative;
    font-size: 14px;
    color: var(--text-secondary);
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

.feature-list li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-size: 18px;
}

/* ===== Steps ===== */
.step-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 50px;
}

.step-card {
    background: var(--bg-white);
    padding: 40px 28px;
    border-radius: var(--radius-lg);
    text-align: center;
    transition: var(--transition);
}

.step-card:hover {
    box-shadow: var(--shadow);
    transform: translateY(-4px);
}

.step-num {
    width: 48px;
    height: 48px;
    margin: 0 auto 20px;
    background: var(--bg-gray);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 600;
    color: var(--primary);
}

.step-card h4 {
    margin-bottom: 8px;
}

.step-card p {
    font-size: 13px;
    margin: 0;
}

/* ===== FAQ ===== */
.faq-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.faq-item {
    background: var(--bg-white);
    padding: 24px 28px;
    border-radius: var(--radius);
}

.faq-item h4 {
    font-size: 15px;
    margin-bottom: 10px;
    font-weight: 500;
}

.faq-item p {
    font-size: 13px;
    margin: 0;
    line-height: 1.7;
}

/* ===== CTA ===== */
.cta-section {
    background: var(--primary);
    padding: 70px 24px;
    text-align: center;
}

.cta-section h2 {
    color: white;
    margin-bottom: 12px;
}

.cta-section p {
    color: rgba(255,255,255,0.85);
    font-size: 16px;
    margin-bottom: 28px;
}

.cta-section .hero-btn {
    background: white;
    color: var(--primary);
}

.cta-section .hero-btn:hover {
    background: var(--bg-gray);
}

/* ===== Footer ===== */
.footer {
    background: #1a1a1a;
    color: #888;
    padding: 40px 24px 24px;
}

.footer-inner {
    max-width: 1400px;
    margin: 0 auto;
}

.footer-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 24px;
    border-bottom: 1px solid #2a2a2a;
    margin-bottom: 20px;
}

.footer-top p { font-size: 13px; }

.footer-links a {
    font-size: 13px;
    margin-left: 20px;
    color: #888;
}

.footer-links a:hover { color: white; }

.footer-bottom {
    font-size: 12px;
    color: #555;
}

/* ===== Loading ===== */
#loading {
    position: fixed;
    inset: 0;
    background: white;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
}

.loader {
    width: 32px;
    height: 32px;
    border: 3px solid var(--bg-gray);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ===== Animation ===== */
.fade-up {
    opacity: 0;
    transform: translateY(24px);
    transition: all 0.5s ease;
}

.fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .hero-content { grid-template-columns: 1fr; text-align: center; }
    .hero-text p { margin: 0 auto 28px; }
    .hero-tags { justify-content: center; }
    .hero-img { order: -1; max-width: 600px; margin: 0 auto; }
    .product-grid { grid-template-columns: repeat(2, 1fr); }
    .feature-row { grid-template-columns: 1fr; gap: 40px; }
    .feature-row.reverse .feature-img { order: 0; }
}

@media (max-width: 768px) {
    h1 { font-size: 36px; }
    h2 { font-size: 30px; }
    .nav { display: none; }
    .banner-grid { grid-template-columns: repeat(2, 1fr); }
    .product-grid, .step-grid, .faq-grid { grid-template-columns: 1fr; }
}