/* ========================================
   SECTION 1: INTRO / HERO - 经典优雅 + 动态增强
   ======================================== */
.section-intro {
    position: relative;
    overflow: hidden;
    background: var(--color-bg-primary);
    flex-direction: column;
    text-align: center;
    justify-content: center;
    padding-top: calc(var(--nav-height) + var(--spacing-md));
    padding-left: var(--spacing-md);
    padding-right: var(--spacing-md);
    padding-bottom: 0;
    min-height: 100vh;
    box-sizing: border-box;
}

/* 背景装饰文字 */
.intro-bg-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: clamp(8rem, 16vw, 18rem);
    font-weight: 700;
    color: transparent;
    -webkit-text-stroke: 1px rgba(201, 169, 97, 0.1);
    font-family: var(--font-serif);
    letter-spacing: 0.05em;
    pointer-events: none;
    z-index: 1;
    opacity: 0;
    animation: fadeIn 2s ease-out 0.5s forwards;
}

/* 亮色主题下的背景文字增强 */
.theme-light .intro-bg-text {
    -webkit-text-stroke: 1px rgba(166, 124, 61, 0.15);
}

/* 几何装饰元素 - 不对称布局 */
.geometric-decoration {
    position: absolute;
    pointer-events: none;
    z-index: 1;
}

.geometric-decoration.line-1 {
    top: 15%;
    right: 10%;
    width: 120px;
    height: 1px;
    background: linear-gradient(to right, transparent, var(--color-accent-gold), transparent);
    animation: slideInRight 1.5s ease-out;
}

.geometric-decoration.line-2 {
    bottom: 20%;
    left: 8%;
    width: 80px;
    height: 1px;
    background: linear-gradient(to right, var(--color-accent-gold), transparent);
    animation: slideInLeft 1.5s ease-out 0.3s backwards;
}

.geometric-decoration.box-1,
.geometric-decoration.box-2 {
    border: 1px solid rgba(201, 169, 97, 0.3);
    animation: floatUpDown 6s ease-in-out infinite;
}

.geometric-decoration.box-1 {
    top: 25%;
    left: 12%;
    width: 60px;
    height: 60px;
}

.geometric-decoration.box-2 {
    bottom: 30%;
    right: 15%;
    width: 40px;
    height: 40px;
    border-color: rgba(201, 169, 97, 0.2);
    animation-delay: 1s;
    animation-duration: 8s;
}

.geometric-decoration.circle-1 {
    top: 40%;
    right: 8%;
    width: 80px;
    height: 80px;
    border: 1px solid rgba(201, 169, 97, 0.15);
    border-radius: var(--radius-full);
    animation: pulse-subtle 4s ease-in-out infinite;
}

/* 亮色主题下的几何装饰增强 */
.theme-light .geometric-decoration.box-1,
.theme-light .geometric-decoration.box-2 {
    border-color: rgba(166, 124, 61, 0.4);
}

.theme-light .geometric-decoration.box-2 {
    border-color: rgba(166, 124, 61, 0.3);
}

.theme-light .geometric-decoration.circle-1 {
    border-color: rgba(166, 124, 61, 0.25);
}

/* 漂浮微粒 */
.floating-particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    pointer-events: none;
    z-index: 1;
}

.particle {
    position: absolute;
    width: 2px;
    height: 2px;
    background: var(--color-accent-gold);
    border-radius: var(--radius-full);
    opacity: 0;
    animation: particleFloat 15s linear infinite;
}

.particle:nth-child(1) { left: 10%; animation-delay: 0s; animation-duration: 12s; }
.particle:nth-child(2) { left: 25%; animation-delay: 3s; animation-duration: 15s; }
.particle:nth-child(3) { left: 40%; animation-delay: 6s; animation-duration: 18s; }
.particle:nth-child(4) { left: 60%; animation-delay: 2s; animation-duration: 14s; }
.particle:nth-child(5) { left: 75%; animation-delay: 8s; animation-duration: 16s; }
.particle:nth-child(6) { left: 90%; animation-delay: 4s; animation-duration: 13s; }

.intro-bg-gradient {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(
        circle at center,
        rgba(201, 169, 97, 0.08) 0%,
        transparent 70%
    );
    pointer-events: none;
    animation: pulse-glow 8s ease-in-out infinite;
}

.intro-layout {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: var(--max-width);
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: var(--spacing-xl);
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    box-sizing: border-box;
}

.intro-title {
    margin-bottom: var(--spacing-lg);
    line-height: 1.1;
    font-family: var(--font-serif);
    font-size: clamp(3rem, 7vw, 4.5rem);
}

.title-line {
    display: block;
    font-weight: 400;
    letter-spacing: -0.02em;
    opacity: 0;
    transform: translateY(30px);
}

.title-line:first-child {
    color: var(--color-text-primary);
    margin-bottom: 0.2em;
    animation: fadeInUp 1s ease-out 0.3s forwards;
}

.title-line:last-child {
    color: var(--color-accent-gold);
    font-style: italic;
    animation: fadeInUp 1s ease-out 0.6s forwards;
}

.intro-summary {
    display: grid;
    grid-template-columns: repeat(2, minmax(240px, 1fr));
    margin-bottom: var(--spacing-lg);
    width: 100%;
    gap: 0;
}

.summary-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) 0;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    transition: border-color var(--transition-fast);
    box-sizing: border-box;
    position: relative;
}

/* 第一列和第三列的右边距 */
.summary-card:nth-child(odd) {
    padding-right: var(--spacing-lg);
}

/* 第二列和第四列的左边距 */
.summary-card:nth-child(even) {
    padding-left: var(--spacing-lg);
}

.summary-card:hover {
    border-top-color: rgba(201, 169, 97, 0.3);
}

/* 亮色主题下的边框增强 */
.theme-light .summary-card {
    border-top-color: rgba(0, 0, 0, 0.12);
}

.theme-light .summary-card:hover {
    border-top-color: rgba(166, 124, 61, 0.4);
}

.summary-badge {
    flex-shrink: 0;
    width: 38px;
    font-size: 0.7rem;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: var(--color-text-muted);
    text-align: center;
    font-weight: 400;
    opacity: 0.6;
}

.summary-text {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 0.15rem;
}

.summary-title {
    font-size: 0.9rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-text-primary);
    margin: 0;
    line-height: 1.2;
    font-weight: 400;
}

.summary-desc {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    letter-spacing: 0.03em;
    margin: 0;
    line-height: 1.3;
    white-space: nowrap;
    opacity: 0.85;
}

.intro-text {
    text-align: left;
    max-width: 520px;
    width: 100%;
    box-sizing: border-box;
}

.intro-eyebrow {
    display: inline-flex;
    letter-spacing: 0.35em;
    text-transform: uppercase;
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
    opacity: 0;
    animation: fadeIn 1s ease-out 0.2s forwards;
}

.intro-lede {
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
    margin-bottom: var(--spacing-md);
    max-width: 36ch;
    opacity: 0;
    animation: fadeIn 1s ease-out 0.8s forwards;
}

.lede-line {
    color: var(--color-text-secondary);
    font-size: 1.125rem;
    line-height: 1.6;
    margin: 0;
    white-space: nowrap;
}

/* ========================================
   Responsive - Hero Section
   ======================================== */

/* 平板和中等屏幕 (769px - 1024px) - 垂直布局确保文字可读性 */
@media (max-width: 1024px) and (min-width: 769px) {
    .intro-layout {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
        padding: var(--spacing-md) var(--spacing-lg);
    }

    .intro-text {
        max-width: 100%;
        text-align: center;
        padding: 0 var(--spacing-md);
    }
    
    .intro-summary {
        grid-template-columns: repeat(2, minmax(240px, 1fr));
        max-width: 650px;
        margin-left: auto;
        margin-right: auto;
    }
}

/* 小屏幕平板 (≤900px) - 单列布局 */
@media (max-width: 900px) {
    .intro-summary {
        grid-template-columns: 1fr;
        max-width: 100%;
    }
    
    .summary-card {
        padding: var(--spacing-xs) 0;
    }
    
    .summary-card:nth-child(odd),
    .summary-card:nth-child(even) {
        padding-left: var(--spacing-md);
        padding-right: var(--spacing-md);
    }
}

/* 移动端 (≤768px) - 大气优雅设计 */
@media (max-width: 768px) {
    .section-intro {
        padding: calc(var(--nav-height) + var(--spacing-lg)) var(--spacing-md) var(--spacing-xl);
        min-height: 100vh;
        box-sizing: border-box;
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .intro-bg-text {
        font-size: clamp(6rem, 25vw, 14rem);
        opacity: 0.15;
        top: 30%;
    }

    .intro-bg-gradient {
        width: 500px;
        height: 500px;
        opacity: 0.6;
    }

    /* 移动端隐藏装饰元素以提升性能 */
    .geometric-decoration,
    .floating-particles {
        display: none;
    }

    .intro-layout {
        grid-template-columns: 1fr;
        gap: var(--spacing-xxl);
        padding: 0;
        box-sizing: border-box;
        width: 100%;
        max-width: 100%;
    }

    /* 移动端 intro-text - 大气设计 */
    .intro-text {
        text-align: center;
        margin: 0 auto;
        max-width: 100%;
        padding: var(--spacing-xl) 0;
        position: relative;
        width: 100%;
        overflow: visible;
    }

    /* 移动端装饰元素 - 使用 emoji/SVG，脱离 DOM 位置 */
    .intro-text::before {
        content: '♪';
        position: absolute;
        top: -30px;
        left: 5%;
        font-size: 4rem;
        color: var(--color-accent-gold);
        opacity: 0.15;
        z-index: -1;
        transform: rotate(-15deg);
        pointer-events: none;
        line-height: 1;
    }

    .intro-text::after {
        content: '♫';
        position: absolute;
        bottom: -40px;
        right: 8%;
        font-size: 3.5rem;
        color: var(--color-accent-gold);
        opacity: 0.12;
        z-index: -1;
        transform: rotate(20deg);
        pointer-events: none;
        line-height: 1;
    }

    /* 移动端额外装饰元素 */
    .intro-title::after {
        content: '🎵';
        position: absolute;
        top: -50px;
        right: 3%;
        font-size: 3rem;
        opacity: 0.2;
        z-index: -1;
        transform: rotate(25deg);
        pointer-events: none;
        line-height: 1;
    }

    .intro-eyebrow {
        margin-bottom: var(--spacing-lg);
        font-size: 0.7rem;
        letter-spacing: 0.4em;
        opacity: 0.8;
        display: block;
    }

    .intro-title {
        margin-bottom: var(--spacing-xl);
        font-size: clamp(3rem, 12vw, 4.5rem);
        line-height: 1.05;
        letter-spacing: -0.03em;
        font-weight: 400;
        position: relative;
    }

    .title-line {
        display: block;
    }

    .title-line:first-child {
        margin-bottom: 0.1em;
        color: var(--color-text-primary);
    }

    .title-line:last-child {
        font-size: 0.85em;
        color: var(--color-accent-gold);
        font-style: italic;
    }

    .intro-lede {
        margin: 0 auto var(--spacing-xl);
        max-width: 90%;
        gap: 0.8rem;
        text-align: center;
        position: relative;
    }

    /* Lede 装饰元素 - 使用音乐符号 */
    .intro-lede::before {
        content: '♪';
        position: absolute;
        left: -50px;
        top: 0;
        font-size: 2.5rem;
        color: var(--color-accent-gold);
        opacity: 0.2;
        transform: rotate(-25deg);
        pointer-events: none;
        line-height: 1;
    }

    .intro-lede::after {
        content: '♫';
        position: absolute;
        right: -50px;
        bottom: 0;
        font-size: 2.5rem;
        color: var(--color-accent-gold);
        opacity: 0.2;
        transform: rotate(25deg);
        pointer-events: none;
        line-height: 1;
    }

    .lede-line {
        font-size: 1.1rem;
        line-height: 1.8;
        white-space: normal;
        color: var(--color-text-secondary);
        font-weight: 300;
        letter-spacing: 0.02em;
    }

    .intro-summary {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        margin: var(--spacing-xl) auto 0;
        width: 100%;
        max-width: 100%;
        gap: 0;
    }
    
    .summary-card {
        display: flex;
        align-items: center;
        justify-content: center;
        gap: var(--spacing-sm);
        padding: var(--spacing-lg) var(--spacing-sm);
        border-top: 1px solid rgba(255, 255, 255, 0.08);
        transition: border-color var(--transition-fast);
        box-sizing: border-box;
        width: 100%;
    }

    .summary-card:hover {
        border-top-color: rgba(201, 169, 97, 0.3);
    }

    .summary-card:nth-child(odd),
    .summary-card:nth-child(even) {
        padding-left: 0;
        padding-right: 0;
    }
    
    .summary-badge {
        flex-shrink: 0;
        width: 35px;
        font-size: 0.65rem;
        letter-spacing: 0.25em;
        text-transform: uppercase;
        color: var(--color-text-muted);
        text-align: center;
        font-weight: 400;
        opacity: 0.6;
    }

    .summary-text {
        flex: 1;
        min-width: 0;
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 0.1rem;
    }

    .summary-title {
        font-size: 0.85rem;
        letter-spacing: 0.1em;
        text-transform: uppercase;
        color: var(--color-text-primary);
        margin: 0;
        line-height: 1.2;
        font-weight: 400;
        text-align: center;
    }

    .summary-desc {
        font-size: 0.75rem;
        color: var(--color-text-secondary);
        letter-spacing: 0.02em;
        margin: 0;
        line-height: 1.3;
        white-space: normal;
        opacity: 0.85;
        text-align: center;
    }

}

/* 小屏幕手机 (≤480px) */
@media (max-width: 480px) {
    .section-intro {
        padding: calc(var(--nav-height) + var(--spacing-md)) var(--spacing-sm) var(--spacing-lg);
    }

    .intro-text {
        padding: var(--spacing-lg) 0;
    }

    .intro-text::before {
        font-size: 3rem;
        top: -25px;
        left: 3%;
    }

    .intro-text::after {
        font-size: 2.5rem;
        bottom: -30px;
        right: 5%;
    }

    .intro-title::after {
        font-size: 2.5rem;
        top: -40px;
        right: 2%;
    }

    .intro-eyebrow {
        margin-bottom: var(--spacing-md);
        font-size: 0.65rem;
    }

    .intro-title {
        font-size: clamp(2.5rem, 10vw, 3.5rem);
        margin-bottom: var(--spacing-lg);
    }

    .intro-lede {
        margin-bottom: var(--spacing-xl);
        max-width: 95%;
    }

    .intro-lede::before {
        font-size: 2rem;
        left: -40px;
    }

    .intro-lede::after {
        font-size: 2rem;
        right: -40px;
    }

    .lede-line {
        font-size: 1rem;
        line-height: 1.7;
    }

    .intro-summary {
        gap: 0;
    }

    .summary-card {
        padding: var(--spacing-md) var(--spacing-xs);
    }

    .summary-badge {
        width: 32px;
        font-size: 0.6rem;
    }

    .summary-title {
        font-size: 0.8rem;
    }

    .summary-desc {
        font-size: 0.7rem;
    }

}