/* ========================================
   青云登科 - 主样式表
   设计风格：清新、大气、现代
   配色：蓝绿渐变 + 白色 + 深灰
   ======================================== */

/* CSS变量定义 */
:root {
    /* 主色调 */
    --primary: #1a73e8;
    --primary-light: #4a9af7;
    --primary-dark: #0d47a1;
    --secondary: #00bfa5;
    --secondary-light: #64dfda;
    --accent: #ff6b35;

    /* 渐变 */
    --gradient-primary: linear-gradient(135deg, #1a73e8 0%, #00bfa5 100%);
    --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #00bfa5 100%);
    --gradient-card: linear-gradient(145deg, #ffffff 0%, #f8faff 100%);

    /* 中性色 */
    --white: #ffffff;
    --gray-50: #fafbff;
    --gray-100: #f5f7fa;
    --gray-200: #e8ecf1;
    --gray-300: #c9d1db;
    --gray-500: #6b7a8d;
    --gray-700: #3a4553;
    --gray-900: #1a202c;

    /* 功能色 */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;

    /* 字体 */
    --font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* 间距 */
    --section-padding: 100px 0;
    --container-max: 1200px;

    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(26, 115, 232, 0.08);
    --shadow-md: 0 4px 20px rgba(26, 115, 232, 0.12);
    --shadow-lg: 0 10px 40px rgba(26, 115, 232, 0.15);
    --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.15);

    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 30px;

    /* 过渡 */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 基础重置 */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-family);
    color: var(--gray-700);
    background-color: var(--white);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* 容器 */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* ========================================
   导航栏
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid transparent;
    transition: var(--transition);
}

.navbar.scrolled {
    border-bottom-color: var(--gray-200);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    font-size: 24px;
    font-weight: 700;
    color: var(--gray-900);
}

.logo-img {
    height: 34px;
    width: auto;
    display: block;
}

.footer-logo .logo-img {
    height: 30px;
}

.logo-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 8px;
}

.nav-links a {
    text-decoration: none;
    color: var(--gray-700);
    font-weight: 500;
    font-size: 15px;
    padding: 8px 18px;
    border-radius: var(--radius-xl);
    transition: var(--transition);
    position: relative;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
    background: rgba(26, 115, 232, 0.08);
}

.btn-nav {
    background: var(--gradient-primary) !important;
    color: var(--white) !important;
    -webkit-text-fill-color: white !important;
    padding: 10px 24px !important;
    font-weight: 600 !important;
}

.btn-nav:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-toggle span {
    width: 24px;
    height: 2px;
    background: var(--gray-700);
    transition: var(--transition);
    border-radius: 2px;
}

/* ========================================
   首页横幅 Hero Section
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding-top: 72px;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.hero-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg,
        #f0f4ff 0%,
        #e8f4f8 30%,
        #f0fff4 60%,
        #fff8f0 100%
    );
}

.hero-particles {
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(26, 115, 232, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(0, 191, 165, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(118, 75, 162, 0.05) 0%, transparent 60%);
}

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

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--white);
    padding: 10px 20px;
    border-radius: var(--radius-xl);
    font-size: 14px;
    font-weight: 500;
    color: var(--primary);
    box-shadow: var(--shadow-md);
    margin-bottom: 24px;
}

.hero h1 {
    font-size: clamp(42px, 6vw, 68px);
    font-weight: 900;
    line-height: 1.15;
    color: var(--gray-900);
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.highlight {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--gray-500);
    margin-bottom: 36px;
    line-height: 1.8;
}

.hero-stats {
    display: flex;
    gap: 40px;
    margin-bottom: 40px;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 36px;
    font-weight: 900;
    color: var(--primary);
    line-height: 1;
}

.stat-label {
    font-size: 14px;
    color: var(--gray-500);
    margin-top: 4px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: var(--radius-xl);
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-family: inherit;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--white);
    box-shadow: 0 4px 20px rgba(26, 115, 232, 0.35);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(26, 115, 232, 0.45);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: var(--white);
}

.btn-large {
    padding: 18px 48px;
    font-size: 18px;
}

.btn-wechat {
    background: #07c160;
    color: var(--white);
    width: 100%;
    margin-top: 12px;
}

.btn-wechat:hover {
    background: #06ad56;
    transform: translateY(-2px);
}

/* Hero 右侧动画卡片 */
.hero-visual {
    position: relative;
    height: 450px;
}

.floating-card {
    position: absolute;
    background: var(--white);
    padding: 20px 28px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
    color: var(--gray-800);
    animation: float 6s ease-in-out infinite;
}

.floating-card .card-icon {
    font-size: 28px;
}

.card-1 {
    top: 10%;
    left: 10%;
    animation-delay: 0s;
}

.card-2 {
    top: 40%;
    right: 5%;
    animation-delay: 2s;
}

.card-3 {
    bottom: 15%;
    left: 25%;
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--gray-500);
    font-size: 13px;
    animation: bounce 2s infinite;
}

.scroll-arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid var(--gray-300);
    border-bottom: 2px solid var(--gray-300);
    transform: rotate(45deg);
}

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(10px); }
}

/* ========================================
   通用区块样式
   ======================================== */
.section {
    padding: var(--section-padding);
    position: relative;
}

.section:nth-child(even) {
    background: var(--gray-50);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    background: linear-gradient(135deg, rgba(26, 115, 232, 0.1), rgba(0, 191, 165, 0.1));
    color: var(--primary);
    padding: 8px 20px;
    border-radius: var(--radius-xl);
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
}

.section-header h2 {
    font-size: clamp(32px, 4vw, 44px);
    font-weight: 800;
    color: var(--gray-900);
    margin-bottom: 16px;
    letter-spacing: -0.5px;
}

.section-header p {
    font-size: 17px;
    color: var(--gray-500);
    max-width: 600px;
    margin: 0 auto;
}

/* ========================================
   核心优势
   ======================================== */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 28px;
}

.advantage-card {
    background: var(--gradient-card);
    padding: 36px 28px;
    border-radius: var(--radius-lg);
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--gray-200);
    position: relative;
    overflow: hidden;
}

.advantage-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: var(--transition);
}

.advantage-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.advantage-card:hover::before {
    transform: scaleX(1);
}

.advantage-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, rgba(26, 115, 232, 0.1), rgba(0, 191, 165, 0.1));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.advantage-icon svg {
    width: 32px;
    height: 32px;
    color: var(--primary);
}

.advantage-card:hover .advantage-icon {
    background: var(--gradient-primary);
    transform: scale(1.1);
}

.advantage-card:hover .advantage-icon svg {
    color: var(--white);
}

.advantage-card h3 {
    font-size: 19px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.advantage-card p {
    font-size: 14px;
    color: var(--gray-500);
    line-height: 1.7;
}

/* ========================================
   学习力提升（新版布局）
   ======================================== */
.learning-block {
    margin-bottom: 56px;
}

.learning-block:last-of-type {
    margin-bottom: 0;
}

.block-title {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 24px;
    font-weight: 800;
    color: var(--gray-900);
    margin-bottom: 28px;
}

.block-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    color: var(--white);
    border-radius: 12px;
    font-size: 18px;
    font-weight: 800;
    flex-shrink: 0;
    box-shadow: var(--shadow-sm);
}

/* 六大学习维度 */
.dimensions-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.dimension-card {
    background: var(--gradient-card);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: 28px 24px;
    text-align: center;
    transition: var(--transition);
}

.dimension-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.dim-icon {
    font-size: 38px;
    margin-bottom: 14px;
}

.dimension-card h4 {
    font-size: 17px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 8px;
}

.dimension-card p {
    font-size: 13px;
    color: var(--gray-500);
    line-height: 1.7;
}

/* 三大核心能力 */
.abilities-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.ability-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 32px 26px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    border-top: 4px solid transparent;
    border-image: var(--gradient-primary) 1;
    transition: var(--transition);
}

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

.ability-icon {
    font-size: 44px;
    margin-bottom: 16px;
}

.ability-card h4 {
    font-size: 18px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 8px;
}

.ability-card p {
    font-size: 14px;
    color: var(--gray-500);
    line-height: 1.7;
}

/* 服务方式 */
.methods-row {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    justify-content: center;
}

.method-pill {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: rgba(26, 115, 232, 0.08);
    color: var(--primary);
    padding: 14px 26px;
    border-radius: var(--radius-xl);
    font-size: 16px;
    font-weight: 600;
    transition: var(--transition);
}

.method-pill:hover {
    background: var(--primary);
    color: var(--white);
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.method-icon {
    font-size: 22px;
}

/* 服务理念 */
.learning-philosophy {
    margin-top: 56px;
    padding: 44px 40px;
    background: var(--gradient-hero);
    border-radius: var(--radius-lg);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.learning-philosophy::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.learning-philosophy p {
    position: relative;
    z-index: 1;
    font-size: 23px;
    font-weight: 700;
    color: var(--white);
    letter-spacing: 0.5px;
}

/* ========================================
   志愿填报
   ======================================== */
.volunteer-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: start;
}

.process-title {
    font-size: 24px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 32px;
    text-align: center;
}

.process-steps {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.step {
    display: flex;
    gap: 20px;
    align-items: flex-start;
    position: relative;
}

.step-number {
    min-width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content h4 {
    font-size: 17px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 4px;
}

.step-content p {
    font-size: 14px;
    color: var(--gray-500);
}

.step-arrow {
    text-align: center;
    font-size: 24px;
    color: var(--gray-300);
    padding: 8px 0 8px 24px;
    font-weight: 300;
}

.volunteer-results {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.result-card {
    background: var(--white);
    padding: 28px 24px;
    border-radius: var(--radius-md);
    text-align: center;
    border: 2px solid var(--gray-200);
    transition: var(--transition);
}

.result-card:hover {
    border-color: var(--primary-light);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.result-card.highlight-result {
    background: var(--gradient-primary);
    border-color: transparent;
    color: var(--white);
}

.result-card.highlight-result:hover {
    transform: translateY(-4px);
}

.result-icon {
    font-size: 40px;
    margin-bottom: 12px;
}

.result-card h4 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 8px;
}

.result-card p {
    font-size: 13px;
    opacity: 0.85;
    line-height: 1.6;
}

/* ========================================
   专家介绍
   ======================================== */
.expert-profile {
    display: grid;
    grid-template-columns: 380px 1fr;
    gap: 60px;
    align-items: center;
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 50px;
    box-shadow: var(--shadow-lg);
}

.expert-photo-wrapper {
    position: relative;
}

.expert-photo {
    width: 100%;
    border-radius: var(--radius-lg);
    object-fit: cover;
    aspect-ratio: 3/4;
    box-shadow: var(--shadow-lg);
}

.photo-frame {
    position: absolute;
    inset: -12px;
    border: 3px solid transparent;
    border-radius: calc(var(--radius-lg) + 12px);
    background: var(--gradient-primary) border-box;
    -webkit-mask: linear-gradient(#fff 0 0) padding-box, linear-gradient(#fff 0 0);
    mask: linear-gradient(#fff 0 0) padding-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    opacity: 0.3;
}

.expert-name-section {
    margin-bottom: 28px;
}

.expert-name {
    font-size: 32px;
    font-weight: 900;
    color: var(--gray-900);
    margin-bottom: 4px;
}

.expert-title {
    font-size: 22px;
    font-weight: 500;
    color: var(--primary);
    margin-left: 8px;
}

.expert-role {
    font-size: 16px;
    color: var(--gray-500);
    font-weight: 500;
}

.expert-credentials {
    display: flex;
    flex-direction: column;
    gap: 14px;
    margin-bottom: 28px;
}

.credential-item {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 15px;
    color: var(--gray-700);
    padding: 10px 16px;
    background: var(--gray-50);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.credential-item:hover {
    background: rgba(26, 115, 232, 0.06);
    transform: translateX(6px);
}

.credential-icon {
    font-size: 20px;
    flex-shrink: 0;
}

.expert-quote {
    padding: 24px 28px;
    background: linear-gradient(135deg, rgba(26, 115, 232, 0.06), rgba(0, 191, 165, 0.06));
    border-left: 4px solid var(--primary);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.expert-quote blockquote {
    font-size: 16px;
    font-style: italic;
    color: var(--gray-700);
    line-height: 1.8;
}

/* ========================================
   关于我们
   ======================================== */
.about-story {
    display: flex;
    flex-direction: column;
    gap: 36px;
    max-width: 800px;
    margin: 0 auto;
}

.story-block {
    background: var(--white);
    padding: 36px 40px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.story-block:hover {
    box-shadow: var(--shadow-md);
}

.story-block h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.story-block h3::before {
    content: '';
    width: 5px;
    height: 24px;
    background: var(--gradient-primary);
    border-radius: 3px;
}

.story-block p {
    font-size: 16px;
    color: var(--gray-600);
    line-height: 1.9;
}

.values-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-top: 16px;
}

.value-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 20px;
    background: var(--gray-50);
    border-radius: var(--radius-md);
    transition: var(--transition);
    font-weight: 600;
    color: var(--gray-700);
    font-size: 14px;
}

.value-item:hover {
    background: var(--gradient-primary);
    color: var(--white);
    transform: translateY(-4px);
}

.value-icon {
    font-size: 32px;
}

/* ========================================
   联系我们
   ======================================== */
.contact-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    margin-bottom: 50px;
}

.contact-card {
    background: var(--white);
    padding: 36px 28px;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--gray-200);
}

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

.contact-card.main-contact {
    background: var(--gradient-primary);
    color: var(--white);
    border: none;
}

.contact-icon {
    font-size: 44px;
    margin-bottom: 16px;
}

.contact-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
}

.contact-value {
    font-size: 24px;
    font-weight: 700;
    display: block;
    margin-bottom: 8px;
}

.contact-card a.contact-value {
    color: inherit;
    text-decoration: none;
}

.contact-desc {
    font-size: 13px;
    opacity: 0.75;
}

.cta-banner {
    background: var(--gradient-hero);
    border-radius: var(--radius-lg);
    padding: 60px 40px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta-banner::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.cta-content {
    position: relative;
    z-index: 1;
}

.cta-banner h3 {
    font-size: 28px;
    font-weight: 800;
    color: var(--white);
    margin-bottom: 12px;
}

.cta-banner p {
    font-size: 17px;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 28px;
}

.cta-banner .btn-primary {
    background: var(--white);
    color: var(--primary);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.cta-banner .btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.25);
}

/* ========================================
   页脚
   ======================================== */
.footer {
    background: var(--gray-900);
    color: var(--gray-300);
    padding: 60px 0 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 50px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
}

.footer-logo .logo-text {
    font-size: 22px;
    font-weight: 700;
    color: var(--white);
    -webkit-text-fill-color: white;
}

.footer-brand p {
    font-size: 14px;
    line-height: 1.8;
    opacity: 0.7;
}

.footer-links h4,
.footer-contact h4 {
    color: var(--white);
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 16px;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: var(--gray-300);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--secondary-light);
}

.footer-contact p {
    font-size: 14px;
    margin-bottom: 8px;
    opacity: 0.7;
}

.footer-bottom {
    padding: 20px 0;
    text-align: center;
    font-size: 13px;
    opacity: 0.5;
}

.footer-bottom a {
    color: inherit;
    text-decoration: none;
}

/* ========================================
   微信弹窗
   ======================================== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(8px);
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.modal-overlay.active {
    display: flex;
    opacity: 1;
}

.modal-content {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 40px;
    max-width: 400px;
    width: 90%;
    position: relative;
    animation: modalIn 0.3s ease;
}

@keyframes modalIn {
    from { transform: scale(0.9) translateY(20px); opacity: 0; }
    to { transform: scale(1) translateY(0); opacity: 1; }
}

.modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 36px;
    height: 36px;
    border: none;
    background: var(--gray-100);
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--gray-500);
    transition: var(--transition);
}

.modal-close:hover {
    background: var(--gray-200);
    color: var(--gray-700);
}

.modal-body h3 {
    text-align: center;
    font-size: 22px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 24px;
}

.qr-placeholder {
    text-align: center;
}

.qr-code {
    width: 200px;
    height: 200px;
    margin: 0 auto 16px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    padding: 10px;
    background: var(--white);
}

.qr-code svg {
    width: 100%;
    height: 100%;
}

.qr-hint {
    font-size: 14px;
    color: var(--gray-500);
    margin-bottom: 4px;
}

.qr-phone {
    font-size: 22px;
    font-weight: 700;
    color: var(--primary);
}

/* ========================================
   返回顶部按钮
   ======================================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    color: var(--white);
    border: none;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
    box-shadow: var(--shadow-md);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

/* ========================================
   响应式设计
   ======================================== */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-stats {
        justify-content: center;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-visual {
        display: none;
    }

    .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .dimensions-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .volunteer-content {
        grid-template-columns: 1fr;
    }

    .expert-profile {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .expert-photo-wrapper {
        max-width: 320px;
        margin: 0 auto;
    }

    .credential-item {
        justify-content: center;
    }

    .contact-cards {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin-left: auto;
        margin-right: auto;
        margin-bottom: 50px;
    }

    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 70px 0;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-lg);
        gap: 4px;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links a {
        padding: 14px 18px;
        border-radius: var(--radius-sm);
    }

    .mobile-toggle {
        display: flex;
    }

    .hero h1 {
        font-size: 36px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

    .hero-stats {
        gap: 24px;
    }

    .stat-number {
        font-size: 28px;
    }

    .advantages-grid {
        grid-template-columns: 1fr;
    }

    .dimensions-grid {
        grid-template-columns: 1fr;
    }

    .abilities-row {
        grid-template-columns: 1fr;
    }

    .block-title {
        font-size: 20px;
    }

    .learning-philosophy {
        padding: 30px 20px;
    }

    .learning-philosophy p {
        font-size: 18px;
    }

    .values-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .expert-profile {
        padding: 30px 24px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .cta-banner {
        padding: 40px 24px;
    }

    .cta-banner h3 {
        font-size: 22px;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 30px;
    }

    .section-header h2 {
        font-size: 28px;
    }

    .process-steps {
        gap: 0;
    }

    .step-arrow {
        display: none;
    }

    .volunteer-results {
        grid-template-columns: 1fr;
    }

    .values-grid {
        grid-template-columns: 1fr 1fr;
    }
}