/* ==================== 全局样式 ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #27ae60;
    --bg-light: #ecf0f1;
    --bg-white: #ffffff;
    --text-dark: #2c3e50;
    --text-gray: #7f8c8d;
    --border-color: #bdc3c7;
    --shadow-md: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 6px 12px rgba(0, 0, 0, 0.15);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Georgia', 'Garamond', serif;
    color: var(--text-dark);
    background-color: var(--bg-white);
    line-height: 1.8;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ==================== 导航栏 ==================== */
.navbar {
    background: var(--primary-color);
    color: white;
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar-content {
    display: flex;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.2rem;
}

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

/* ==================== 引子区 ==================== */
.intro {
    padding: 4rem 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    text-align: center;
}

.intro-title {
    font-size: 1rem;
    font-weight: 400;
    letter-spacing: 1px;
    margin-bottom: 0.75rem;
    opacity: 0.9;
}

.intro-headline {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.intro-description {
    font-size: 1.1rem;
    opacity: 0.95;
}

/* ==================== 科学讲解区 ==================== */
.science-intro {
    padding: 4rem 0;
    background: var(--bg-white);
}

.section-title {
    font-size: 1.8rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 2.5rem;
    color: var(--primary-color);
}

.science-section {
    margin-bottom: 3rem;
    line-height: 1.9;
}

.subsection-title {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--secondary-color);
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 0.5rem;
}

.science-section p {
    margin-bottom: 1rem;
    color: var(--text-gray);
    font-size: 0.95rem;
}

.science-list {
    list-style: none;
    padding: 1rem 0;
    margin-left: 0;
}

.science-list li {
    padding: 0.75rem 0;
    padding-left: 2rem;
    position: relative;
    color: var(--text-gray);
}

.science-list li:before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: 700;
}

/* ==================== 研究数据区 ==================== */
.research-data {
    padding: 4rem 0;
    background: var(--bg-light);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.research-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 0.5rem;
    text-align: center;
    border-left: 4px solid var(--secondary-color);
    box-shadow: var(--shadow-md);
}

.research-number {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.research-card p {
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.research-card small {
    display: block;
    font-size: 0.8rem;
    color: var(--text-gray);
    font-style: italic;
}

/* ==================== 量表介绍 ==================== */
.scales-intro {
    padding: 4rem 0;
    background: var(--bg-white);
}

.scales-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.scale-card {
    background: var(--bg-light);
    padding: 1.5rem;
    border-radius: 0.5rem;
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
}

.scale-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
    background: white;
}

.scale-icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: 0.75rem;
}

.scale-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
}

.scale-card p {
    font-size: 0.85rem;
    color: var(--text-gray);
}

.scale-detail {
    margin-top: 0.5rem;
    font-style: italic;
    color: var(--text-gray);
}

/* ==================== 学术认可区 ==================== */
.academic-credibility {
    padding: 4rem 0;
    background: var(--bg-light);
}

.credibility-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.credibility-item {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-md);
}

.credibility-item h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.credibility-item ul {
    list-style: none;
}

.credibility-item li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    font-size: 0.9rem;
    color: var(--text-gray);
}

.credibility-item li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-weight: 700;
}

/* ==================== 工具说明区 ==================== */
.tool-explanation {
    padding: 4rem 0;
    background: var(--bg-white);
}

.tool-intro-text {
    text-align: center;
    font-size: 1.1rem;
    margin-bottom: 2rem;
    color: var(--text-gray);
}

.tool-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.feature {
    background: linear-gradient(135deg, rgba(52, 152, 219, 0.1), rgba(39, 174, 96, 0.1));
    padding: 1.5rem;
    border-radius: 0.5rem;
    border-left: 3px solid var(--secondary-color);
}

.feature h3 {
    font-size: 1rem;
    margin-bottom: 0.75rem;
    color: var(--primary-color);
}

.feature p {
    font-size: 0.9rem;
    color: var(--text-gray);
}

/* ==================== FAQ区 ==================== */
.faq-academic {
    padding: 4rem 0;
    background: var(--bg-light);
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.faq-item {
    background: var(--bg-white);
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-md);
}

.faq-item h3 {
    font-size: 0.95rem;
    margin-bottom: 0.75rem;
    color: var(--secondary-color);
    font-weight: 700;
}

.faq-item p {
    font-size: 0.85rem;
    color: var(--text-gray);
    line-height: 1.7;
}

/* ==================== 专家推荐区 ==================== */
.expert-recommendation {
    padding: 4rem 0;
    background: var(--bg-white);
}

.recommendation-intro {
    text-align: center;
    font-size: 1.05rem;
    margin-bottom: 2rem;
    color: var(--text-gray);
}

.experts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.expert-card {
    background: linear-gradient(135deg, rgba(52, 152, 219, 0.05), rgba(52, 152, 219, 0.1));
    border-left: 3px solid var(--secondary-color);
    padding: 1.5rem;
    border-radius: 0.5rem;
}

.expert-quote {
    font-size: 0.9rem;
    color: var(--text-dark);
    line-height: 1.8;
    margin-bottom: 1rem;
    font-style: italic;
}

.expert-name {
    font-size: 0.85rem;
    color: var(--secondary-color);
    font-weight: 600;
}

/* ==================== CTA区 ==================== */
.final-cta {
    padding: 4rem 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    text-align: center;
}

.final-cta h2 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.final-cta p {
    font-size: 1rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.btn {
    display: inline-block;
    padding: 1.5rem 3.5rem;
    background: white;
    color: var(--primary-color);
    border: none;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.3rem;
    transition: all 0.3s ease;
    cursor: pointer;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
}

.btn-large {
    padding: 1.5rem 3.5rem;
    font-size: 1.3rem;
}

.btn-hero {
    display: inline-block;
    padding: 1.5rem 3.5rem;
    background: var(--secondary-color);
    color: white;
    border: none;
    border-radius: 0.75rem;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.3rem;
    transition: all 0.3s ease;
    cursor: pointer;
    box-shadow: 0 8px 25px rgba(52, 152, 219, 0.4);
    text-align: center;
}

.btn-hero:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 35px rgba(52, 152, 219, 0.5);
}

.cta-note {
    margin-top: 1.5rem;
    font-size: 0.9rem;
    opacity: 0.85;
}

/* ==================== 页脚 ==================== */
.footer {
    background: var(--primary-color);
    color: white;
    padding: 2rem 0;
    text-align: center;
    font-size: 0.85rem;
    opacity: 0.9;
}

.footer-credit {
    margin-bottom: 0.5rem;
}

.footer-copyright {
    opacity: 0.7;
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }

    .navbar {
        padding: 1rem 0;
    }

    .logo {
        font-size: 1rem;
    }

    .intro {
        padding: 2rem 0;
    }

    .intro-title {
        font-size: 0.9rem;
    }

    .intro-headline {
        font-size: 1.5rem;
        margin-bottom: 0.75rem;
    }

    .intro-description {
        font-size: 1rem;
    }

    .science-intro {
        padding: 2rem 0;
    }

    .section-title {
        font-size: 1.3rem;
        margin-bottom: 1.5rem;
    }

    .science-section {
        margin-bottom: 2rem;
    }

    .subsection-title {
        font-size: 1.1rem;
        margin-bottom: 0.75rem;
    }

    .science-section p {
        font-size: 0.95rem;
        margin-bottom: 0.75rem;
    }

    .science-list li {
        padding: 0.6rem 0;
        padding-left: 1.5rem;
        font-size: 0.9rem;
    }

    .research-data {
        padding: 2rem 0;
    }

    .research-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .research-card {
        padding: 1.5rem;
    }

    .research-number {
        font-size: 1.8rem;
    }

    .research-card p {
        font-size: 0.9rem;
    }

    .research-card small {
        font-size: 0.75rem;
    }

    .scales-intro {
        padding: 2rem 0;
    }

    .scales-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .scale-card {
        padding: 1.2rem;
    }

    .scale-icon {
        font-size: 2rem;
    }

    .scale-card h3 {
        font-size: 1rem;
    }

    .scale-card p,
    .scale-detail {
        font-size: 0.85rem;
    }

    .academic-credibility {
        padding: 2rem 0;
    }

    .credibility-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .credibility-item {
        padding: 1.5rem;
    }

    .credibility-item h3 {
        font-size: 1rem;
        margin-bottom: 0.75rem;
    }

    .credibility-item li {
        padding: 0.5rem 0;
        font-size: 0.85rem;
    }

    .tool-explanation {
        padding: 2rem 0;
    }

    .tool-intro-text {
        font-size: 1rem;
    }

    .tool-features {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .feature {
        padding: 1.2rem;
    }

    .feature h3 {
        font-size: 0.95rem;
    }

    .feature p {
        font-size: 0.85rem;
    }

    .faq-academic {
        padding: 2rem 0;
    }

    .faq-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .faq-item {
        padding: 1.2rem;
    }

    .faq-item h3 {
        font-size: 0.9rem;
    }

    .faq-item p {
        font-size: 0.85rem;
    }

    .expert-recommendation {
        padding: 2rem 0;
    }

    .recommendation-intro {
        font-size: 1rem;
    }

    .experts-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .expert-card {
        padding: 1.2rem;
    }

    .expert-quote {
        font-size: 0.85rem;
        margin-bottom: 0.75rem;
    }

    .expert-name {
        font-size: 0.8rem;
    }

    .final-cta {
        padding: 2rem 0;
    }

    .final-cta h2 {
        font-size: 1.3rem;
        margin-bottom: 1rem;
    }

    .final-cta p {
        font-size: 1rem;
        margin-bottom: 1.5rem;
    }

    .btn {
        width: 100%;
        padding: 0.9rem 1.5rem;
        font-size: 1rem;
    }

    .btn-large {
        padding: 1rem 1.5rem;
    }

    .btn-hero {
        width: 100%;
        padding: 1.2rem 2rem;
        font-size: 1.1rem;
    }

    .cta-note {
        font-size: 0.85rem;
    }

    .footer {
        padding: 1.5rem 0;
        font-size: 0.8rem;
    }

    .footer-credit {
        font-size: 0.8rem;
    }
}