/* ========================================
   叮格考研官网样式
   设计风格：专业严谨 + 人文温度
   主色：深蓝色 (#1a1a2e, #16213e)
   辅助色：温暖色调 (#f59e0b)
   ======================================== */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background: #0f0f1a;
    color: #e2e8f0;
    line-height: 1.6;
    min-height: 100vh;
}

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

a:hover {
    color: #f59e0b;
}

ul {
    list-style: none;
}

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

/* ---------- 容器 ---------- */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- 导航栏 ---------- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(15, 15, 26, 0.9);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    height: 72px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.25rem;
    font-weight: 600;
}

.logo-icon {
    font-size: 1.5rem;
}

.logo-text {
    background: linear-gradient(135deg, #fff 0%, #a0aec0 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-menu a {
    font-size: 0.95rem;
    color: #a0aec0;
    padding: 8px 0;
    position: relative;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: #fff;
}

.nav-menu a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: #f59e0b;
    border-radius: 2px;
}

.nav-cta {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    color: #fff !important;
    padding: 10px 20px !important;
    border-radius: 8px;
    font-weight: 500;
}

.nav-cta:hover {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    transform: translateY(-1px);
}

/* 移动端菜单按钮 */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: #a0aec0;
    border-radius: 2px;
    transition: all 0.3s;
}

/* ---------- Hero 区域 ---------- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 24px 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse at 30% 20%, rgba(37, 99, 235, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 80%, rgba(245, 158, 11, 0.1) 0%, transparent 50%),
        linear-gradient(135deg, #0f0f1a 0%, #1a1a2e 50%, #16213e 100%);
    z-index: -1;
}

.hero-content {
    text-align: center;
    max-width: 800px;
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 24px;
}

.title-main {
    display: block;
    color: #fff;
}

.title-highlight {
    display: block;
    background: linear-gradient(135deg, #f59e0b 0%, #fbbf24 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: #a0aec0;
    margin-bottom: 16px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-desc {
    font-size: 1.1rem;
    color: #64748b;
    margin-bottom: 40px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: #64748b;
    font-size: 0.85rem;
    animation: float 2s ease-in-out infinite;
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    border-right: 2px solid #64748b;
    border-bottom: 2px solid #64748b;
    transform: rotate(45deg);
}

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

/* ---------- 按钮 ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    color: #fff;
    box-shadow: 0 4px 20px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(37, 99, 235, 0.4);
    color: #fff;
}

.btn-secondary {
    background: transparent;
    color: #a0aec0;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
    color: #fff;
}

.btn-large {
    padding: 18px 36px;
    font-size: 1.1rem;
}

/* ---------- Section 通用 ---------- */
.section {
    padding: 100px 0;
}

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

.section-tag {
    display: inline-block;
    background: rgba(245, 158, 11, 0.1);
    color: #f59e0b;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 16px;
}

.section-title {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    font-weight: 700;
    color: #fff;
    margin-bottom: 16px;
}

.section-desc {
    font-size: 1.1rem;
    color: #64748b;
    max-width: 600px;
    margin: 0 auto;
}

/* ---------- 核心理念 ---------- */
.section-core {
    background: linear-gradient(180deg, #0f0f1a 0%, #1a1a2e 100%);
}

.core-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.core-card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 16px;
    padding: 40px 32px;
    text-align: center;
    transition: all 0.3s;
}

.core-card:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(245, 158, 11, 0.3);
    transform: translateY(-4px);
}

.core-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.core-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #fff;
    margin-bottom: 12px;
}

.core-card p {
    color: #64748b;
    line-height: 1.7;
}

/* ---------- 差异化 ---------- */
.section-diff {
    background: #1a1a2e;
}

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

.diff-text .section-tag,
.diff-text .section-title {
    text-align: left;
}

.diff-text .section-title {
    margin-bottom: 32px;
}

.diff-list {
    margin-bottom: 32px;
}

.diff-list li {
    display: flex;
    gap: 16px;
    margin-bottom: 24px;
}

.diff-icon {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    background: rgba(245, 158, 11, 0.1);
    color: #f59e0b;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
}

.diff-list strong {
    display: block;
    color: #fff;
    margin-bottom: 4px;
}

.diff-list p {
    color: #64748b;
    font-size: 0.95rem;
}

.diff-visual {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.visual-card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    padding: 24px;
}

.visual-card.highlight {
    background: rgba(37, 99, 235, 0.1);
    border-color: rgba(37, 99, 235, 0.3);
}

.visual-header {
    font-size: 0.85rem;
    color: #64748b;
    margin-bottom: 16px;
}

.visual-content {
    display: flex;
    align-items: center;
    gap: 12px;
}

.visual-item {
    background: rgba(255, 255, 255, 0.1);
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 500;
}

.visual-item.faded {
    opacity: 0.3;
}

.visual-card.highlight .visual-item {
    background: rgba(37, 99, 235, 0.3);
}

.visual-arrow {
    color: #64748b;
    font-size: 1.2rem;
}

/* ---------- 师资亮点 ---------- */
.section-team {
    background: linear-gradient(180deg, #1a1a2e 0%, #16213e 100%);
}

.team-showcase {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 60px;
    align-items: center;
}

.team-photo {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 16px;
    aspect-ratio: 3/4;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 16px;
}

.photo-placeholder {
    font-size: 4rem;
    opacity: 0.3;
}

.photo-note {
    color: #64748b;
    font-size: 0.9rem;
}

.team-intro {
    padding: 20px 0;
}

.team-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 24px;
}

.badge {
    background: rgba(37, 99, 235, 0.1);
    color: #60a5fa;
    padding: 6px 14px;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 500;
}

.team-desc {
    font-size: 1.1rem;
    color: #a0aec0;
    line-height: 1.8;
    margin-bottom: 20px;
}

/* ---------- 特色 ---------- */
.section-features {
    background: #16213e;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.feature-card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 16px;
    padding: 32px;
    transition: all 0.3s;
}

.feature-card:hover {
    background: rgba(255, 255, 255, 0.05);
    transform: translateY(-2px);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #fff;
    margin-bottom: 12px;
}

.feature-card p {
    color: #64748b;
    line-height: 1.7;
}

/* ---------- CTA ---------- */
.section-cta {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    position: relative;
    overflow: hidden;
}

.section-cta::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(ellipse, rgba(37, 99, 235, 0.2) 0%, transparent 70%);
    pointer-events: none;
}

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

.cta-content h2 {
    font-size: 2rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 16px;
}

.cta-content p {
    font-size: 1.1rem;
    color: #64748b;
    margin-bottom: 32px;
}

/* ---------- 页脚 ---------- */
.footer {
    background: #0a0a14;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.footer-desc {
    color: #64748b;
    font-size: 0.95rem;
    line-height: 1.7;
}

.footer-links h4 {
    color: #fff;
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.footer-links li,
.footer-links p {
    color: #64748b;
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.footer-icp {
    margin-top: 8px;
    color: #475569 !important;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    padding-top: 20px;
    text-align: center;
}

.footer-bottom p {
    color: #475569;
    font-size: 0.85rem;
}

/* ---------- 响应式设计 ---------- */
@media (max-width: 1024px) {
    .diff-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .diff-visual {
        order: -1;
    }
    
    .team-showcase {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .team-photo {
        max-width: 300px;
        margin: 0 auto;
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: rgba(15, 15, 26, 0.98);
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s;
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .core-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    
    .hero {
        padding: 100px 20px 60px;
    }
    
    .section {
        padding: 60px 0;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .hero-scroll {
        display: none;
    }
}