/* =========================================================
   饼干姐姐剧场 - 温暖治愈系剧集推荐
   完整样式表 (style.css)
   风格：治愈系奶油色调 + 柔和渐变 + 毛玻璃质感
   ========================================================= */

/* === 设计变量：高可读性颜色系统 === */
:root {
    --bg-light: #FFFDF9;               /* 暖白背景 */
    --bg-secondary-light: #FDF6EC;     /* 奶油副背景 */
    --text-primary-light: #2D3A3A;     /* 深灰绿，正文高对比 */
    --text-secondary-light: #5A6B6B;   /* 次级文字 */
    --text-heading-light: #1F2A2A;     /* 标题近黑 */
    --text-link-light: #3D7E75;        /* 治愈系深绿链接 */
    --card-bg-light: #FFFFFF;
    --border-light: #E8DCC8;           /* 暖灰边框 */
    --footer-bg-light: #2C3E3E;        /* 深墨绿 */
    --footer-text-light: #E8F0F0;
    --brand-color: #4A8B7E;            /* 品牌治愈绿 */
    --brand-color-2: #C49B74;          /* 饼干暖棕 */
    --button-text-light: #FFFFFF;
    --button-bg-light: #4A8B7E;
    --nav-bg-light: rgba(255, 253, 249, 0.88);
    --shadow-light: 0 8px 32px rgba(74, 139, 126, 0.08);
    --shadow-hover: 0 12px 40px rgba(74, 139, 126, 0.15);
    --gradient-banner: linear-gradient(135deg, #FDE8D0 0%, #F5D0A9 35%, #D4E8D0 100%);
    --gradient-card: linear-gradient(145deg, #FFFDF9 0%, #FDF6EC 100%);
    --gradient-btn: linear-gradient(135deg, #4A8B7E 0%, #3D7E75 100%);
    --radius-lg: 32px;
    --radius-md: 24px;
    --radius-sm: 16px;

    /* dark 模式变量 */
    --bg-dark: #1A2424;
    --bg-secondary-dark: #223030;
    --text-primary-dark: #DCE8E8;
    --text-secondary-dark: #A8B8B8;
    --text-heading-dark: #F0F7F7;
    --text-link-dark: #7FC8B8;
    --card-bg-dark: #223030;
    --border-dark: #384A4A;
    --footer-bg-dark: #121A1A;
    --footer-text-dark: #B8C8C8;
    --button-text-dark: #F0F7F7;
    --button-bg-dark: #3D7E75;
    --nav-bg-dark: rgba(26, 36, 36, 0.9);
    --shadow-dark: 0 8px 32px rgba(0, 0, 0, 0.3);
    --gradient-banner-dark: linear-gradient(135deg, #1A2E2E 0%, #223A3A 50%, #2C3E3E 100%);
    --gradient-card-dark: linear-gradient(145deg, #1E2A2A 0%, #243232 100%);
}

/* === 基础样式 === */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    background-color: var(--bg-light);
    background-image: radial-gradient(circle at 15% 20%, rgba(196, 155, 116, 0.06) 0%, transparent 40%),
                      radial-gradient(circle at 85% 75%, rgba(74, 139, 126, 0.06) 0%, transparent 40%);
    color: var(--text-primary-light);
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    line-height: 1.75;
    transition: background-color 0.4s ease, color 0.4s ease;
    min-height: 100vh;
}

body.dark-mode {
    background-color: var(--bg-dark);
    background-image: radial-gradient(circle at 15% 20%, rgba(74, 139, 126, 0.08) 0%, transparent 40%),
                      radial-gradient(circle at 85% 75%, rgba(196, 155, 116, 0.05) 0%, transparent 40%);
    color: var(--text-primary-dark);
}

h1, h2, h3, h4, h5, h6 {
    color: var(--text-heading-light);
    font-weight: 600;
    line-height: 1.3;
    transition: color 0.4s ease;
    letter-spacing: -0.02em;
}

body.dark-mode h1,
body.dark-mode h2,
body.dark-mode h3,
body.dark-mode h4,
body.dark-mode h5,
body.dark-mode h6 {
    color: var(--text-heading-dark);
}

p {
    margin-bottom: 1em;
}

a {
    color: var(--text-link-light);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
    position: relative;
}

a:hover {
    color: var(--brand-color);
}

body.dark-mode a {
    color: var(--text-link-dark);
}

body.dark-mode a:hover {
    color: #A0E0D0;
}

p, li, blockquote, figcaption, td, th, span {
    color: inherit;
}

.text-secondary {
    color: var(--text-secondary-light) !important;
}

body.dark-mode .text-secondary {
    color: var(--text-secondary-dark) !important;
}

img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-sm);
}

/* === 容器 === */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
    position: relative;
}

/* === 导航栏 === */
.navbar {
    background-color: var(--nav-bg-light);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--border-light);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.04);
    transition: background-color 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
}

body.dark-mode .navbar {
    background-color: var(--nav-bg-dark);
    border-bottom: 1px solid var(--border-dark);
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.2);
}

.navbar.scrolled {
    box-shadow: 0 6px 30px rgba(0, 0, 0, 0.08);
}

.nav-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
    position: relative;
}

.logo a {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-heading-light);
    letter-spacing: 1px;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: color 0.3s;
}

.logo a::before {
    content: '🍪';
    font-size: 1.4rem;
    filter: drop-shadow(0 2px 4px rgba(196, 155, 116, 0.3));
}

body.dark-mode .logo a {
    color: var(--text-heading-dark);
}

.nav-links {
    display: flex;
    gap: 32px;
    align-items: center;
}

.nav-links a {
    font-weight: 500;
    color: var(--text-primary-light);
    font-size: 0.95rem;
    padding: 6px 2px;
    position: relative;
    transition: color 0.3s;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--brand-color);
    border-radius: 2px;
    transition: width 0.3s ease;
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

body.dark-mode .nav-links a {
    color: var(--text-primary-dark);
}

.nav-links a:hover {
    color: var(--brand-color);
}

body.dark-mode .nav-links a:hover {
    color: var(--text-link-dark);
}

.menu-toggle {
    display: none;
    font-size: 1.8rem;
    background: none;
    border: none;
    color: var(--text-primary-light);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 8px;
    transition: background 0.2s;
}

.menu-toggle:hover {
    background: rgba(0, 0, 0, 0.05);
}

body.dark-mode .menu-toggle {
    color: var(--text-primary-dark);
}

body.dark-mode .menu-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* 移动菜单 */
.mobile-menu {
    display: none;
    flex-direction: column;
    background: var(--card-bg-light);
    padding: 20px 24px;
    gap: 8px;
    border-top: 1px solid var(--border-light);
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 999;
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.08);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    animation: menuSlideDown 0.3s ease;
}

@keyframes menuSlideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

body.dark-mode .mobile-menu {
    background: var(--card-bg-dark);
    border-top-color: var(--border-dark);
}

.mobile-menu a {
    font-size: 1.05rem;
    padding: 10px 12px;
    color: var(--text-primary-light);
    border-radius: 8px;
    transition: background 0.2s;
}

.mobile-menu a:hover {
    background: rgba(74, 139, 126, 0.1);
}

body.dark-mode .mobile-menu a {
    color: var(--text-primary-dark);
}

body.dark-mode .mobile-menu a:hover {
    background: rgba(74, 139, 126, 0.2);
}

.mobile-menu .theme-toggle {
    margin-top: 8px;
    padding: 10px 12px;
    text-align: left;
    width: 100%;
}

/* === 按钮 === */
.btn {
    display: inline-block;
    padding: 12px 32px;
    background: var(--gradient-btn);
    color: var(--button-text-light);
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: none;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(74, 139, 126, 0.25);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.btn:hover::before {
    left: 100%;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(74, 139, 126, 0.35);
}

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

body.dark-mode .btn {
    background: var(--gradient-btn);
    color: var(--button-text-dark);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

/* === 卡片 === */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 28px;
}

.card {
    background: var(--card-bg-light);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    padding: 32px;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-btn);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.card::after {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(74, 139, 126, 0.05) 0%, transparent 70%);
    opacity: 0;
    transition: opacity 0.4s ease;
    pointer-events: none;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
    border-color: rgba(74, 139, 126, 0.3);
}

.card:hover::before {
    opacity: 1;
}

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

body.dark-mode .card {
    background: var(--card-bg-dark);
    border-color: var(--border-dark);
}

body.dark-mode .card:hover {
    border-color: rgba(74, 139, 126, 0.4);
}

.card h3 {
    margin-top: 0;
    margin-bottom: 12px;
    font-size: 1.25rem;
    transition: color 0.3s;
}

.card:hover h3 {
    color: var(--brand-color);
}

.card p {
    color: var(--text-secondary-light);
    margin-bottom: 16px;
}

body.dark-mode .card p {
    color: var(--text-secondary-dark);
}

.card a {
    color: var(--brand-color);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: gap 0.3s ease;
}

.card a:hover {
    gap: 12px;
    color: var(--brand-color);
}

/* 文章卡片日期 */
.article-meta {
    color: var(--text-secondary-light);
    font-size: 0.85rem;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
}

.article-meta::before {
    content: '📅';
    font-size: 0.9em;
}

body.dark-mode .article-meta {
    color: var(--text-secondary-dark);
}

/* === 滚动动画 (Intersection Observer 会添加 .visible) === */
.fade-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* === 首屏 Banner === */
.banner {
    background: var(--gradient-banner);
    border-radius: var(--radius-lg);
    padding: 64px 48px;
    margin: 40px 0;
    color: #2D3A3A;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-light);
    animation: bannerFadeIn 1s ease;
}

@keyframes bannerFadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.banner::before {
    content: '';
    position: absolute;
    top: -30%;
    right: -10%;
    width: 60%;
    height: 80%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.3) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.banner::after {
    content: '🍪';
    position: absolute;
    bottom: -20px;
    right: 40px;
    font-size: 120px;
    opacity: 0.15;
    transform: rotate(-15deg);
    animation: floatCookie 4s ease-in-out infinite;
}

@keyframes floatCookie {
    0%, 100% {
        transform: rotate(-15deg) translateY(0);
    }
    50% {
        transform: rotate(-10deg) translateY(-10px);
    }
}

.banner h1 {
    font-size: clamp(1.8rem, 4vw, 2.8rem);
    margin-bottom: 16px;
    color: var(--text-heading-light);
    line-height: 1.2;
    position: relative;
    z-index: 1;
}

.banner h2 {
    font-size: clamp(1.5rem, 3vw, 2.2rem);
    margin-bottom: 16px;
    color: var(--text-heading-light);
    position: relative;
    z-index: 1;
}

.banner p {
    font-size: 1.15rem;
    margin-bottom: 12px;
    position: relative;
    z-index: 1;
    max-width: 70%;
}

.banner .btn {
    margin-top: 12px;
    position: relative;
    z-index: 1;
}

body.dark-mode .banner {
    background: var(--gradient-banner-dark);
    color: var(--text-primary-dark);
    box-shadow: var(--shadow-dark);
}

body.dark-mode .banner::before {
    background: radial-gradient(circle, rgba(255, 255, 255, 0.05) 0%, transparent 70%);
}

body.dark-mode .banner h1,
body.dark-mode .banner h2 {
    color: var(--text-heading-dark);
}

body.dark-mode .banner p {
    color: var(--text-secondary-dark);
}

/* === 区块通用样式 === */
section {
    margin: 56px 0;
    position: relative;
}

section > h2 {
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    margin-bottom: 20px;
    position: relative;
    display: inline-block;
}

section > h2::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 60px;
    height: 3px;
    background: var(--gradient-btn);
    border-radius: 3px;
}

/* === 关于我们区块 === */
.about-content {
    display: flex;
    flex-wrap: wrap;
    gap: 32px;
    align-items: stretch;
}

.about-text {
    flex: 2;
    min-width: 280px;
}

.about-text p {
    margin-bottom: 16px;
    line-height: 1.9;
}

.about-card {
    flex: 1;
    min-width: 240px;
    background: var(--card-bg-light);
    padding: 28px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-light);
    transition: transform 0.3s, box-shadow 0.3s;
}

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

body.dark-mode .about-card {
    background: var(--card-bg-dark);
    border-color: var(--border-dark);
}

.about-card h3 {
    margin-top: 0;
    margin-bottom: 16px;
    color: var(--brand-color);
}

.about-card ul {
    list-style: none;
    padding: 0;
}

.about-card ul li {
    padding: 8px 0;
    border-bottom: 1px dashed var(--border-light);
    display: flex;
    align-items: center;
    gap: 8px;
}

.about-card ul li:last-child {
    border-bottom: none;
}

.about-card ul li::before {
    content: '✦';
    color: var(--brand-color-2);
}

body.dark-mode .about-card ul li {
    border-bottom-color: var(--border-dark);
}

address {
    font-style: normal;
    background: var(--card-bg-light);
    padding: 20px 24px;
    border-radius: var(--radius-sm);
    border-left: 4px solid var(--brand-color);
    margin-top: 20px;
    line-height: 2;
}

body.dark-mode address {
    background: var(--card-bg-dark);
}

/* === 解决方案区块 === */
.solution-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
}

.solution-item {
    background: var(--gradient-card);
    padding: 28px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-light);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.solution-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--gradient-btn);
    opacity: 0;
    transition: opacity 0.3s;
}

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

.solution-item:hover::before {
    opacity: 1;
}

.solution-item h3 {
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.solution-item h3::after {
    content: attr(data-icon);
    font-size: 1.5em;
}

.solution-item p {
    color: var(--text-secondary-light);
    margin-bottom: 0;
}

body.dark-mode .solution-item {
    background: var(--gradient-card-dark);
    border-color: var(--border-dark);
}

body.dark-mode .solution-item p {
    color: var(--text-secondary-dark);
}

/* === 评价区块 === */
.testimonial-card {
    background: var(--card-bg-light);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    padding: 32px;
    position: relative;
    transition: all 0.3s ease;
}

.testimonial-card::before {
    content: '"';
    position: absolute;
    top: 8px;
    left: 20px;
    font-size: 5rem;
    color: var(--brand-color-2);
    opacity: 0.2;
    font-family: Georgia, serif;
    line-height: 1;
}

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

.testimonial-card p {
    font-size: 1.05rem;
    line-height: 1.8;
    margin-bottom: 16px;
    position: relative;
    z-index: 1;
}

.testimonial-card footer {
    color: var(--brand-color);
    font-weight: 600;
    font-size: 0.9rem;
    border-top: 1px solid var(--border-light);
    padding-top: 12px;
    margin-top: 8px;
}

body.dark-mode .testimonial-card {
    background: var(--card-bg-dark);
    border-color: var(--border-dark);
}

body.dark-mode .testimonial-card footer {
    border-top-color: var(--border-dark);
}

/* === FAQ 样式 === */
.faq-item {
    border-bottom: 1px solid var(--border-light);
    padding: 8px 0;
    transition: border-color 0.3s;
}

body.dark-mode .faq-item {
    border-bottom-color: var(--border-dark);
}

.faq-question {
    font-weight: 600;
    cursor: pointer;
    font-size: 1.05rem;
    color: var(--text-heading-light);
    padding: 16px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    transition: color 0.3s;
    user-select: none;
}

.faq-question::after {
    content: '＋';
    font-size: 1.3rem;
    color: var(--brand-color);
    transition: transform 0.3s ease;
    flex-shrink: 0;
}

.faq-question:hover {
    color: var(--brand-color);
}

.faq-question.active::after {
    transform: rotate(45deg);
}

body.dark-mode .faq-question {
    color: var(--text-heading-dark);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease, opacity 0.3s ease;
    opacity: 0;
    padding: 0;
    margin: 0;
}

.faq-answer.open {
    max-height: 500px;
    opacity: 1;
    padding: 0 0 16px 0;
    margin-bottom: 12px;
}

.faq-answer-inner {
    padding: 12px 16px;
    border-left: 3px solid var(--brand-color);
    background: rgba(74, 139, 126, 0.05);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    line-height: 1.8;
}

body.dark-mode .faq-answer-inner {
    background: rgba(74, 139, 126, 0.1);
}

/* === HowTo 区块 === */
.howto {
    background: var(--card-bg-light);
    border-radius: var(--radius-lg);
    padding: 48px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-light);
    position: relative;
    overflow: hidden;
}

.howto::before {
    content: '📖';
    position: absolute;
    top: 20px;
    right: 30px;
    font-size: 100px;
    opacity: 0.05;
    transform: rotate(10deg);
}

body.dark-mode .howto {
    background: var(--card-bg-dark);
    border-color: var(--border-dark);
}

.howto ol {
    padding-left: 0;
    list-style: none;
    counter-reset: step;
    margin: 24px 0;
}

.howto ol li {
    counter-increment: step;
    padding: 12px 0 12px 48px;
    position: relative;
    line-height: 1.8;
    border-bottom: 1px dashed var(--border-light);
}

.howto ol li:last-child {
    border-bottom: none;
}

.howto ol li::before {
    content: counter(step);
    position: absolute;
    left: 0;
    top: 12px;
    width: 32px;
    height: 32px;
    background: var(--gradient-btn);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
    box-shadow: 0 2px 8px rgba(74, 139, 126, 0.3);
}

body.dark-mode .howto ol li {
    border-bottom-color: var(--border-dark);
}

.howto strong {
    color: var(--brand-color);
}

/* === 表格 === */
.info-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    border-radius: var(--radius-sm);
    overflow: hidden;
    box-shadow: var(--shadow-light);
}

.info-table th {
    background: var(--gradient-btn);
    color: white;
    font-weight: 600;
    text-align: left;
    padding: 14px 16px;
    font-size: 0.95rem;
}

.info-table td {
    background: var(--card-bg-light);
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-light);
    transition: background 0.2s;
}

.info-table tr:hover td {
    background: rgba(74, 139, 126, 0.05);
}

.info-table tr:last-child td {
    border-bottom: none;
}

body.dark-mode .info-table td {
    background: var(--card-bg-dark);
    border-bottom-color: var(--border-dark);
}

body.dark-mode .info-table tr:hover td {
    background: rgba(74, 139, 126, 0.1);
}

/* === 搜索框 === */
.search-box {
    display: flex;
    gap: 12px;
    max-width: 500px;
    margin: 24px 0;
}

.search-box input {
    flex: 1;
    padding: 12px 24px;
    border-radius: 50px;
    border: 1px solid var(--border-light);
    background: var(--card-bg-light);
    color: var(--text-primary-light);
    font-size: 0.95rem;
    transition: all 0.3s ease;
    outline: none;
}

.search-box input:focus {
    border-color: var(--brand-color);
    box-shadow: 0 0 0 3px rgba(74, 139, 126, 0.15);
}

body.dark-mode .search-box input {
    background: var(--card-bg-dark);
    border-color: var(--border-dark);
    color: var(--text-primary-dark);
}

body.dark-mode .search-box input:focus {
    border-color: var(--brand-color);
    box-shadow: 0 0 0 3px rgba(74, 139, 126, 0.2);
}

/* === 主题切换与返回顶部按钮 === */
.theme-toggle {
    background: none;
    border: 1px solid var(--border-light);
    border-radius: 50px;
    padding: 8px 16px;
    cursor: pointer;
    color: var(--text-primary-light);
    font-size: 1rem;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.theme-toggle:hover {
    background: rgba(74, 139, 126, 0.1);
    border-color: var(--brand-color);
    transform: scale(1.05);
}

body.dark-mode .theme-toggle {
    border-color: var(--border-dark);
    color: var(--text-primary-dark);
}

body.dark-mode .theme-toggle:hover {
    background: rgba(74, 139, 126, 0.2);
    border-color: var(--brand-color);
}

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 100;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: none;
    background: var(--gradient-btn);
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(74, 139, 126, 0.3);
    transition: all 0.3s ease;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(74, 139, 126, 0.4);
}

body.dark-mode .back-to-top {
    background: var(--gradient-btn);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

/* === Footer === */
.site-footer {
    background-color: var(--footer-bg-light);
    color: var(--footer-text-light);
    padding: 64px 0 24px;
    margin-top: 80px;
    position: relative;
    overflow: hidden;
}

.site-footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--brand-color), var(--brand-color-2), var(--brand-color));
}

body.dark-mode .site-footer {
    background-color: var(--footer-bg-dark);
    color: var(--footer-text-dark);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    margin-bottom: 48px;
}

.footer-col h4 {
    color: #F0F7F7;
    margin-bottom: 20px;
    font-size: 1.1rem;
    position: relative;
    padding-bottom: 10px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background: var(--brand-color-2);
}

body.dark-mode .footer-col h4 {
    color: #E8F0F0;
}

.footer-col p {
    color: #B8C8C8;
    line-height: 1.8;
}

.footer-col a {
    color: #A8B8B8;
    transition: color 0.3s;
    margin: 4px 0;
    display: inline-block;
}

.footer-col a:hover {
    color: var(--brand-color-2);
}

body.dark-mode .footer-col a {
    color: #8A9A9A;
}

body.dark-mode .footer-col a:hover {
    color: #D4E8D0;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 24px;
    font-size: 0.9rem;
    color: #8A9A9A;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

body.dark-mode .footer-bottom {
    border-top-color: rgba(255, 255, 255, 0.05);
}

/* === SVG 图标通用 === */
.svg-icon {
    background: var(--card-bg-light);
    border-radius: 12px;
    padding: 8px;
    transition: all 0.3s ease;
}

.svg-icon:hover {
    background: var(--brand-color);
    color: white;
}

body.dark-mode .svg-icon {
    background: var(--card-bg-dark);
}

/* === 响应式 === */
@media (max-width: 1024px) {
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 32px;
    }

    .banner p {
        max-width: 85%;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }

    .nav-links {
        display: none;
    }

    .menu-toggle {
        display: block;
    }

    .mobile-menu.open {
        display: flex;
    }

    .banner {
        padding: 48px 28px;
        border-radius: var(--radius-md);
    }

    .banner p {
        max-width: 100%;
        font-size: 1.05rem;
    }

    .banner::after {
        font-size: 80px;
        right: 20px;
        bottom: -10px;
    }

    .card-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    section {
        margin: 40px 0;
    }

    .howto {
        padding: 32px 24px;
    }

    .about-content {
        flex-direction: column;
    }

    .testimonial-card {
        padding: 24px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .banner {
        padding: 40px 24px;
    }

    .banner h1 {
        font-size: 1.6rem;
    }

    .banner h2 {
        font-size: 1.3rem;
    }

    .banner::after {
        display: none;
    }

    .btn {
        padding: 10px 24px;
        font-size: 0.9rem;
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 44px;
        height: 44px;
    }
}

/* === 无障碍：高对比度支持 === */
@media (prefers-contrast: high) {
    :root {
        --text-primary-light: #1A1A1A;
        --text-secondary-light: #333333;
        --text-heading-light: #000000;
        --border-light: #666666;
        --text-primary-dark: #FFFFFF;
        --text-secondary-dark: #E0E0E0;
        --text-heading-dark: #FFFFFF;
        --border-dark: #999999;
    }
}

/* === 减少动态效果 === */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* === 滚动条美化 === */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-light);
}

::-webkit-scrollbar-thumb {
    background: var(--brand-color);
    border-radius: 5px;
    opacity: 0.6;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--brand-color-2);
}

body.dark-mode ::-webkit-scrollbar-track {
    background: var(--bg-dark);
}

/* === 打印样式 === */
@media print {
    .navbar,
    .back-to-top,
    .theme-toggle,
    .menu-toggle,
    .mobile-menu {
        display: none !important;
    }

    body {
        background: white;
        color: black;
    }

    .card,
    .solution-item,
    .testimonial-card,
    .howto,
    .banner {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}