/* =========================================
   1. 基础重置与变量
   ========================================= */
:root {
    --primary-color: #1a2a3a;
    --accent-color: #c5a065;
    --gold-color: #d4af37;
    --white: #ffffff;
    --gray-light: #f5f5f5;
    --gray-medium: #e0e0e0;
    --gray-dark: #666666;
    --font-sans: 'Arial', 'Microsoft YaHei', sans-serif;
    --font-serif: 'Georgia', 'Microsoft YaHei', serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-sans);
    line-height: 1.6;
    color: var(--gray-dark);
    background-color: var(--white);
}

h1, h2, h3, h4 {
    font-family: var(--font-serif);
    font-weight: normal;
}

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

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

/* =========================================
   2. 通用样式
   ========================================= */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.section-title {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    text-align: center;
}

.section-section {
    padding: 80px 0;
}

/* Reveal 动画效果 */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* =========================================
   3. 导航栏样式
   ========================================= */
header {
    background-color: #0f172a;
    color: var(--white);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    height: 70px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 30px;
    transition: all 0.3s ease;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.8rem;
    font-weight: bold;
    letter-spacing: 2px;
}

.logo a {
    display: flex;
    align-items: center;
    color: var(--white);
    text-decoration: none;
}

.logo-img {
    width: 45px;
    height: 45px;
    margin-right: 15px;
    border-radius: 50%;
}

.logo-ace {
    color: var(--gold-color);
}

.logo-tutor {
    color: var(--white);
}

nav ul {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 2.5rem;
}

nav ul li a {
    color: var(--white);
    font-size: 1.05rem;
    transition: all 0.3s ease;
    padding: 0.5rem 0;
    font-weight: 500;
    position: relative;
}

nav ul li a:hover,
nav ul li a.active {
    color: var(--accent-color);
}

nav ul li a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--accent-color);
}

/* 汉堡菜单按钮（小屏幕） */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    padding: 10px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--white);
    margin: 3px 0;
    transition: all 0.3s ease;
}

/* 响应式设计 - 小屏幕 */
@media (max-width: 768px) {
    header {
        padding: 0 15px;
    }
    
    .logo {
        font-size: 1.4rem;
    }
    
    .logo-img {
        width: 40px;
        height: 40px;
    }
    
    nav ul {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background-color: #0f172a;
        padding: 20px 0;
        gap: 1.5rem;
        text-align: center;
        box-shadow: 0 10px 20px rgba(0,0,0,0.2);
    }
    
    nav ul.show {
        display: flex;
    }
    
    .hamburger {
        display: flex;
    }
    
    /* 汉堡菜单动画 */
    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }
    
    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }
}

/* 滚动效果 */
header.scrolled {
    background-color: rgba(15, 23, 42, 0.98);
    box-shadow: 0 4px 20px rgba(0,0,0,0.15);
    backdrop-filter: blur(10px);
}

/* =========================================
   4. 子页面顶部 Hero
   ========================================= */
.sub-page-hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, #0f172a 100%);
    height: 200px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--white);
    padding-top: 70px;
    margin-bottom: 40px;
}

.sub-page-hero h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.sub-page-hero p {
    font-size: 1.1rem;
    color: var(--accent-color);
    letter-spacing: 2px;
}

@media (max-width: 768px) {
    .sub-page-hero {
        height: 160px;
    }
    
    .sub-page-hero h1 {
        font-size: 1.8rem;
    }
}

/* =========================================
   5. 英雄区域样式
   ========================================= */
.hero {
    background: linear-gradient(rgba(26, 42, 58, 0.88), rgba(26, 42, 58, 0.88)), 
                url('https://picsum.photos/seed/education/1920/1080.jpg') center/cover no-repeat;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--white);
    padding-top: 70px;
}

.hero-content h1 {
    font-size: 3.5rem;
    margin-bottom: 1.2rem;
    font-weight: bold;
    text-shadow: 2px 2px 10px rgba(0,0,0,0.3);
}

.hero-content p {
    font-size: 1.25rem;
    margin-bottom: 2.5rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
    opacity: 0.95;
}

.btn {
    display: inline-block;
    background-color: var(--accent-color);
    color: var(--white);
    padding: 14px 40px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: bold;
    transition: all 0.3s ease;
    border: 2px solid var(--accent-color);
    cursor: pointer;
    font-size: 1.05rem;
}

.btn:hover {
    background-color: transparent;
    color: var(--accent-color);
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(197, 160, 101, 0.3);
}

@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 2.2rem;
    }
    
    .hero-content p {
        font-size: 1rem;
        margin-bottom: 2rem;
    }
}

/* =========================================
   6. 功能区域样式
   ========================================= */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    background: var(--white);
    padding: 2.5rem 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.1);
}

.icon-box {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    font-size: 1.35rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.feature-card p {
    color: var(--gray-dark);
    line-height: 1.8;
}

/* =========================================
   7. 博客区域样式
   ========================================= */
.blog-list {
    max-width: 800px;
    margin: 0 auto;
}

.blog-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 1.5rem;
    padding: 1.8rem;
    border: 1px solid #eee;
    transition: all 0.3s ease;
    cursor: pointer;
    border-radius: 8px;
}

.blog-item:hover {
    border-color: var(--accent-color);
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    transform: translateY(-3px);
}

.blog-date {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), #0f172a);
    color: var(--white);
    min-width: 80px;
    height: 80px;
    border-radius: 10px;
    margin-right: 2rem;
    flex-shrink: 0;
}

.blog-date .day {
    font-size: 1.8rem;
    font-weight: bold;
    line-height: 1;
}

.blog-date .month {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 3px;
}

.blog-content h3 {
    font-size: 1.25rem;
    margin-bottom: 0.6rem;
    color: var(--primary-color);
}

.blog-content p {
    color: var(--gray-dark);
    font-size: 0.95rem;
    line-height: 1.7;
}

.more-blogs-btn {
    text-align: center;
    margin-top: 3rem;
}

.more-blogs-btn a {
    display: inline-block;
    background-color: var(--accent-color);
    color: var(--white);
    padding: 12px 35px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: bold;
    transition: all 0.3s ease;
}

.more-blogs-btn a:hover {
    background-color: #b8955f;
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(197, 160, 101, 0.3);
}

@media (max-width: 768px) {
    .blog-item {
        flex-direction: column;
        text-align: center;
    }
    
    .blog-date {
        margin-right: 0;
        margin-bottom: 1rem;
        min-width: 70px;
        height: 70px;
    }
    
    .blog-date .day {
        font-size: 1.5rem;
    }
}

/* =========================================
   8. 师资团队样式
   ========================================= */
.tutors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.tutor-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    cursor: pointer;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.tutor-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.12);
}

.tutor-img-container {
    position: relative;
    height: 240px;
    overflow: hidden;
}

.tutor-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}

.tutor-card:hover .tutor-img {
    transform: scale(1.08);
}

.tutor-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(26, 42, 58, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.tutor-card:hover .tutor-overlay {
    opacity: 1;
}

.click-hint {
    color: var(--white);
    font-size: 1.1rem;
    font-weight: bold;
    padding: 10px 20px;
    border: 2px solid var(--white);
    border-radius: 25px;
}

.tutor-info {
    padding: 1.8rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.tutor-name {
    font-size: 1.3rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.tutor-subject {
    color: #888;
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.tutor-brief {
    color: #666;
    font-size: 0.9rem;
    line-height: 1.6;
    margin-bottom: 1rem;
    flex-grow: 1;
}

.tutor-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tutor-tag {
    background-color: #f4f6f8;
    color: #666;
    padding: 5px 12px;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
}

/* =========================================
   9. 模态框样式
   ========================================= */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.75);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: #fff;
    padding: 35px;
    border-radius: 15px;
    max-width: 420px;
    text-align: center;
    position: relative;
    transform: scale(0.85);
    transition: transform 0.3s ease;
}

.modal-overlay.active .modal-content {
    transform: scale(1);
}

.modal-content-large {
    max-width: 800px;
    text-align: left;
}

.close-modal {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 32px;
    cursor: pointer;
    color: #666;
    transition: color 0.3s ease;
    line-height: 1;
}

.close-modal:hover {
    color: var(--accent-color);
}

.modal-header h3 {
    margin-bottom: 10px;
    color: var(--primary-color);
    font-size: 1.4rem;
}

.modal-header p {
    color: #666;
    margin-bottom: 25px;
}

.qr-code-wrapper {
    margin: 25px 0;
}

.qr-code-img {
    width: 220px;
    height: 220px;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.modal-footer-text {
    color: #666;
    margin-top: 25px;
    font-size: 0.95rem;
}

/* 博客详情模态框 */
.blog-detail-content {
    padding: 20px 10px 10px;
    line-height: 1.9;
    color: #444;
    max-height: 70vh;
    overflow-y: auto;
}

.blog-detail-content h3 {
    color: var(--primary-color);
    margin-top: 25px;
    margin-bottom: 15px;
    font-size: 1.4rem;
}

.blog-detail-content p {
    margin-bottom: 18px;
    font-size: 1rem;
}

.blog-detail-content strong {
    color: var(--accent-color);
    font-weight: bold;
}

.blog-detail-content h4 {
    color: var(--primary-color);
    margin-top: 30px;
    margin-bottom: 12px;
    font-size: 1.15rem;
}

/* =========================================
   10. 底部栏样式
   ========================================= */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 4rem 0 2rem;
    margin-top: 6rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2.5rem;
    margin-bottom: 2.5rem;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--white);
    transition: color 0.3s ease;
    font-size: 1rem;
}

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

.copyright {
    text-align: center;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    color: #aaa;
}

.filing-info {
    text-align: center;
    font-size: 0.85rem;
    color: #aaa;
}

.filing-info a {
    color: #aaa;
}

@media (max-width: 768px) {
    .footer-links {
        gap: 1.5rem;
    }
    
    .footer-links a {
        font-size: 0.9rem;
    }
}

/* =========================================
   11. 响应式设计优化
   ========================================= */
@media (max-width: 768px) {
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid, .tutors-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        margin: 20px;
        max-width: calc(100% - 40px);
    }
    
    .modal-content-large {
        max-height: 85vh;
        overflow-y: auto;
    }
}