* {
    box-sizing: border-box;
}

::before,
::after {
    box-sizing: border-box;
}

:root {
    --amber-primary: #d84315;
    --amber-secondary: #bf360c;
    --amber-light: #fffbeb;
    --amber-100: #fef3c7;
    --amber-500: #f59e0b;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
}

body {
    background-color: #fffaf0;
    color: #5d4037;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

.container {
    width: 100%;
    margin-left: auto;
    margin-right: auto;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
    box-sizing: border-box;
}

.max-w-7xl {
    max-width: 80rem;
}

.max-w-6xl {
    max-width: 72rem;
}

.max-w-4xl {
    max-width: 56rem;
}

/* Navigation */
.nav-bar {
    padding: 1.5rem 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--amber-primary);
    display: flex;
    align-items: center;
    text-decoration: none;
}

.nav-logo i {
    margin-right: 0.5rem;
}

.nav-links {
    display: none;
    gap: 2rem;
}

@media (min-width: 768px) {
    .nav-links {
        display: flex;
    }
}

.nav-links a {
    text-decoration: none;
    color: inherit;
    transition: all 0.15s ease-in-out;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--amber-primary);
}

.nav-links a.active {
    font-weight: 700;
}

/* Hero Section */
header.hero {
    flex-grow: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 7rem 0;
}

.hero-content {
    text-align: center;
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    color: var(--amber-primary);
    margin-bottom: 1.5rem;
    line-height: 1;
}

@media (min-width: 768px) {
    .hero-title {
        font-size: 4.5rem;
    }
}

.hero-title-highlight {
    display: block;
    font-size: 0.55em;
    font-weight: 600;
    color: var(--amber-500);
    margin-top: 0.5rem;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--gray-600);
    margin-bottom: 2.5rem;
    line-height: 1.75;
}

@media (min-width: 768px) {
    .hero-subtitle {
        font-size: 1.25rem;
    }
}

.hero-buttons {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 1rem;
}

@media (min-width: 768px) {
    .hero-buttons {
        flex-direction: row;
    }
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-auth {
    display: none;
    align-items: center;
    gap: 0.75rem;
}

@media (min-width: 768px) {
    .nav-auth {
        display: flex;
    }
}

.hero-auth-actions {
    margin-top: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

@media (min-width: 768px) {
    .hero-auth-actions {
        display: none;
    }
}

.btn {
    padding: 1rem 2rem;
    border-radius: 9999px;
    font-weight: 700;
    font-size: 1.125rem;
    text-decoration: none;
    transition: all 0.15s ease-in-out;
    display: inline-block;
}

.btn:hover {
    transform: translateY(-0.25rem);
}

.btn-primary {
    background-color: var(--amber-primary);
    color: #fff;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
}

.btn-primary:hover {
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
}

.btn-secondary {
    background-color: #fff;
    color: var(--amber-primary);
    border: 2px solid var(--amber-primary);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
}

.btn-secondary:hover {
    background-color: var(--amber-light);
}

/* Background Section */
.section-bg {
    background-color: #fff;
    padding: 7rem 0;
}

.section-title {
    font-size: 1.875rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 4rem;
}

.section-title-dark {
    color: var(--gray-600);
}

.section-title-accent {
    color: var(--amber-primary);
}

/* Pain Points Section - 垂直时间线布局 */
.pain-points-section {
    background: linear-gradient(180deg, #fffaf0 0%, #fff 100%);
    padding: 7rem 0;
}

.timeline {
    position: relative;
    padding: 2rem 0;
}

.timeline-line {
    position: absolute;
    left: 2.5rem;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, var(--amber-primary), var(--amber-500), rgba(217, 119, 6, 0.2));
    border-radius: 2px;
}

@media (min-width: 768px) {
    .timeline-line {
        left: 50%;
        transform: translateX(-50%);
    }
}

.timeline-item {
    position: relative;
    display: flex;
    align-items: flex-start;
    margin-bottom: 3rem;
    padding-left: 6rem;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

@media (min-width: 768px) {
    .timeline-item {
        padding-left: 0;
        justify-content: center;
    }

    .timeline-item:nth-child(odd) {
        flex-direction: row-reverse;
        padding-right: calc(50% + 2rem);
    }

    .timeline-item:nth-child(even) {
        padding-left: calc(50% + 2rem);
    }
}

.timeline-marker {
    position: absolute;
    left: 0;
    width: 5rem;
    height: 5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2;
}

@media (min-width: 768px) {
    .timeline-marker {
        left: 50%;
        transform: translateX(-50%);
    }
}

.timeline-number {
    width: 4rem;
    height: 4rem;
    background: linear-gradient(135deg, var(--amber-primary), var(--amber-500));
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 700;
    box-shadow: 0 4px 15px rgba(217, 119, 6, 0.4);
    transition: all 0.3s ease;
}

.timeline-item:hover .timeline-number {
    transform: scale(1.1);
    box-shadow: 0 6px 20px rgba(217, 119, 6, 0.5);
}

.timeline-content {
    background: #fff;
    padding: 1.5rem 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    border: 1px solid var(--gray-100);
    flex: 1;
    max-width: 400px;
    transition: all 0.3s ease;
}

.timeline-content:hover {
    transform: translateX(8px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
    border-color: var(--amber-200);
}

@media (min-width: 768px) {
    .timeline-item:nth-child(odd) .timeline-content:hover {
        transform: translateX(-8px);
    }

    .timeline-item:nth-child(even) .timeline-content:hover {
        transform: translateX(8px);
    }
}

.timeline-icon {
    width: 3rem;
    height: 3rem;
    background: var(--amber-100);
    color: var(--amber-primary);
    border-radius: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.timeline-content h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--gray-600);
    margin-bottom: 0.5rem;
}

.timeline-content p {
    color: var(--gray-500);
    margin: 0;
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Core Features Section */
.core-features-section {
    background: #fff;
    padding: 7rem 0;
    text-align: center;
}

.core-features-description {
    font-size: 1.125rem;
    color: var(--gray-600);
    line-height: 1.8;
    max-width: 800px;
    margin: 0 auto;
}

.highlight-text {
    color: var(--amber-primary);
    font-weight: 600;
    background: var(--amber-100);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
}

/* Advantages Section */
.advantages-section {
    background: var(--gray-50);
    padding: 7rem 0;
}

.advantages-grid {
    display: grid;
    gap: 2rem;
}

@media (min-width: 768px) {
    .advantages-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.advantage-card {
    background: #fff;
    padding: 2rem 1.5rem;
    border-radius: 1rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    border: 1px solid var(--gray-100);
    transition: all 0.15s ease-in-out;
}

.advantage-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
    border-color: var(--amber-100);
}

.advantage-icon {
    width: 4rem;
    height: 4rem;
    background: linear-gradient(135deg, var(--amber-100), #fff);
    color: var(--amber-primary);
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    font-size: 1.75rem;
}

.advantage-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--gray-600);
    margin-bottom: 1rem;
}

.advantage-card p {
    color: var(--gray-500);
    margin: 0;
    font-size: 0.95rem;
    line-height: 1.6;
}


/* ========== Experiments Section - 单卡片飞入飞出轮播 ========== */
.experiments-section {
    padding: 7rem 0;
    background: var(--gray-50);
}

.experiments-intro {
    text-align: center;
    color: var(--gray-500);
    font-size: 1.1rem;
    margin-top: -2rem;
    margin-bottom: 3rem;
}

/* 轮播容器 */
.carousel-container {
    position: relative;
    padding: 0 4rem;
    max-width: 1200px;
    margin: 0 auto;
}

@media (max-width: 768px) {
    .carousel-container {
        padding: 0 2rem;
    }
}

/* 单卡片视口 */
.carousel-viewport {
    position: relative;
    min-height: 400px;
    padding: 2rem 0;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* 卡片基础样式 */
.carousel-card {
    position: absolute;
    width: 80%;
    max-width: 500px;
    transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1),
    opacity 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    left: 50%;
    transform: translateX(-50%);
}

.carousel-card.current {
    z-index: 2;
    opacity: 1;
}

/* 卡片内容 */
.carousel-card .experiment-card {
    background: #fff;
    padding: 2.5rem;
    border-radius: 1.5rem;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
    border: 1px solid var(--amber-200);
    text-decoration: none;
    display: flex;
    flex-direction: column;
    height: 100%;
}

/* 飞出动画 - 向左飞出 */
.carousel-card.slide-out-left {
    animation: slideOutLeft 0.5s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* 飞出动画 - 向右飞出 */
.carousel-card.slide-out-right {
    animation: slideOutRight 0.5s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* 飞入动画 - 从左侧飞入 */
.carousel-card.slide-in-left {
    animation: slideInFromLeft 0.5s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* 飞入动画 - 从右侧飞入 */
.carousel-card.slide-in-right {
    animation: slideInFromRight 0.5s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* 动画关键帧 */
@keyframes slideOutLeft {
    0% {
        transform: translateX(-50%) scale(1);
        opacity: 1;
    }

    100% {
        transform: translateX(-150vw) scale(0.7);
        opacity: 0;
    }
}

@keyframes slideOutRight {
    0% {
        transform: translateX(-50%) scale(1);
        opacity: 1;
    }

    100% {
        transform: translateX(50vw) scale(0.7);
        opacity: 0;
    }
}

@keyframes slideInFromLeft {
    0% {
        transform: translateX(-150vw) scale(0.7);
        opacity: 0;
    }

    100% {
        transform: translateX(-50%) scale(1);
        opacity: 1;
    }
}

@keyframes slideInFromRight {
    0% {
        transform: translateX(50vw) scale(0.7);
        opacity: 0;
    }

    100% {
        transform: translateX(-50%) scale(1);
        opacity: 1;
    }
}

/* 实验卡片样式 */
.experiment-category {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--amber-500);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 0.75rem;
}

.experiment-name {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-600);
    margin-bottom: 0.75rem;
    line-height: 1.3;
}

.experiment-desc {
    color: var(--gray-500);
    margin-bottom: 1.5rem;
    flex-grow: 1;
    line-height: 1.6;
    font-size: 1rem;
}

.experiment-card .badge {
    align-self: flex-start;
}

/* 轮播箭头 */
.carousel-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 3rem;
    height: 3rem;
    border-radius: 50%;
    background: #fff;
    border: 2px solid var(--amber-200);
    color: var(--amber-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    transition: all 0.2s ease;
    z-index: 10;
}

.carousel-arrow:hover {
    background: var(--amber-primary);
    border-color: var(--amber-primary);
    color: #fff;
    transform: translateY(-50%) scale(1.1);
    box-shadow: 0 6px 16px rgba(217, 119, 6, 0.3);
}

.carousel-arrow:active {
    transform: translateY(-50%) scale(0.95);
}

.carousel-prev {
    left: 0;
}

.carousel-next {
    right: 0;
}

/* 指示器 */
.carousel-dots {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 2.5rem;
}

.carousel-dots .dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    border: none;
    background: var(--gray-200);
    cursor: pointer;
    transition: all 0.2s ease;
}

.carousel-dots .dot:hover {
    background: var(--amber-300);
}

.carousel-dots .dot.active {
    background: var(--amber-primary);
    transform: scale(1.2);
}

/* 隐藏数据存储 */
.carousel-data {
    display: none;
}

.footer {
    padding: 3rem 1.5rem;
    margin-top: 5rem;
}

.footer-text {
    max-width: 80rem;
    margin: 0 auto;
    text-align: center;
    color: var(--gray-500);
    font-size: 0.875rem;
}