/* ========================================
   罗金楠 - RokingLar
   深黑极简 · INS高级质感风格
   ======================================== */

/* ---------- CSS 变量 ---------- */
:root {
    --bg-dark: #0a0a0a;
    --bg-dark-secondary: #141414;
    --bg-dark-tertiary: #1a1a1a;
    --text-white: #ffffff;
    --text-gray: #888888;
    --text-gray-light: #666666;
    --accent: #ffffff;
    --border-color: rgba(255, 255, 255, 0.08);
    --font-serif: 'Noto Serif SC', serif;
    --font-sans: 'Inter', sans-serif;
    --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-dark);
    color: var(--text-white);
    line-height: 1.7;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

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

::selection {
    background: rgba(255, 255, 255, 0.2);
    color: var(--text-white);
}

/* ---------- 容器 ---------- */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 40px;
}

/* ---------- 导航栏 ---------- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(20px);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.nav-logo {
    font-family: var(--font-sans);
    font-size: 1.1rem;
    font-weight: 500;
    letter-spacing: 2px;
    color: var(--text-white);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 50px;
}

.nav-link {
    font-size: 0.85rem;
    font-weight: 400;
    letter-spacing: 1px;
    color: var(--text-gray);
    position: relative;
    padding: 5px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--text-white);
    transition: width 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-white);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    font-size: 1.5rem;
    color: var(--text-white);
    cursor: pointer;
}

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

.hero-bg {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, rgba(20, 20, 20, 1) 0%, rgba(10, 10, 10, 1) 100%);
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 0 20px;
}

.hero-label {
    font-size: 0.85rem;
    letter-spacing: 4px;
    color: var(--text-gray);
    margin-bottom: 20px;
    text-transform: uppercase;
}

.hero-title {
    font-family: var(--font-serif);
    font-size: clamp(3rem, 10vw, 6rem);
    font-weight: 400;
    color: var(--text-white);
    margin-bottom: 20px;
    letter-spacing: 8px;
}

.title-line {
    display: block;
    width: 60px;
    height: 1px;
    background: var(--text-gray);
    margin: 30px auto 0;
}

.hero-subtitle {
    font-family: var(--font-serif);
    font-size: clamp(1rem, 2vw, 1.2rem);
    color: var(--text-gray-light);
    font-weight: 300;
    margin-bottom: 15px;
    letter-spacing: 3px;
}

.hero-tags {
    font-size: 0.8rem;
    color: var(--text-gray);
    letter-spacing: 2px;
    margin-bottom: 60px;
}

.hero-scroll {
    margin-top: 40px;
}

.scroll-link {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    color: var(--text-gray);
}

.scroll-text {
    font-size: 0.75rem;
    letter-spacing: 2px;
    text-transform: uppercase;
}

.scroll-link i {
    font-size: 1.2rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(10px); }
    60% { transform: translateY(5px); }
}

/* ---------- 通用样式 ---------- */
.section-padding {
    padding: 120px 0;
}

.section-muted {
    background: var(--bg-dark-secondary);
}

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

.section-label {
    font-size: 0.75rem;
    letter-spacing: 4px;
    color: var(--text-gray);
    text-transform: uppercase;
    margin-bottom: 15px;
}

.section-title {
    font-family: var(--font-serif);
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 400;
    color: var(--text-white);
    margin-bottom: 20px;
}

.title-underline {
    width: 40px;
    height: 1px;
    background: var(--text-gray);
}

.title-underline.mx-auto {
    margin: 0 auto;
}

/* ---------- 关于区域 ---------- */
.about-content {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.about-quote {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    color: var(--text-gray-light);
    font-weight: 300;
    line-height: 2.4;
    margin-top: 30px;
    padding: 40px 50px;
    background: var(--bg-dark-secondary);
    border-left: 3px solid var(--text-gray);
    text-align: left;
    letter-spacing: 1px;
}

/* ---------- 学习记录区域 ---------- */
.study-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin-bottom: 60px;
}

.study-card {
    background: var(--bg-dark-tertiary);
    border: 1px solid var(--border-color);
    padding: 40px;
    transition: var(--transition);
}

.study-card:hover {
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-5px);
}

.study-card-inner {
    text-align: center;
}

.study-card-title {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    font-weight: 400;
    color: var(--text-white);
    margin-bottom: 15px;
}

.study-card-subtitle {
    font-size: 0.85rem;
    color: var(--text-gray);
    letter-spacing: 1px;
}

/* ---------- 旅行足迹时间线 ---------- */
.travel-timeline {
    max-width: 600px;
    margin: 0 auto;
}

.timeline-title {
    font-family: var(--font-serif);
    font-size: 1.2rem;
    font-weight: 400;
    color: var(--text-white);
    text-align: center;
    margin-bottom: 40px;
    letter-spacing: 2px;
}

.timeline-title i {
    margin-right: 10px;
    color: var(--text-gray);
}

.timeline {
    position: relative;
    padding-left: 30px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 5px;
    top: 0;
    bottom: 0;
    width: 1px;
    background: var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 40px;
}

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

.timeline-dot {
    position: absolute;
    left: -30px;
    top: 5px;
    width: 11px;
    height: 11px;
    background: var(--bg-dark);
    border: 2px solid var(--text-gray);
    border-radius: 50%;
}

.timeline-content {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 15px;
}

.timeline-date {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--text-gray);
    min-width: 70px;
}

.timeline-location {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    color: var(--text-white);
}

.timeline-pages {
    font-size: 0.8rem;
    color: var(--text-gray);
}

/* ---------- 光影随笔区域 ---------- */
.photo-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.photo-card {
    overflow: hidden;
}

.photo-wrapper {
    position: relative;
    aspect-ratio: 4/3;
    overflow: hidden;
}

.photo-wrapper img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: grayscale(30%);
    transition: var(--transition);
}

.photo-card:hover .photo-wrapper img {
    transform: scale(1.05);
    filter: grayscale(0%);
}

/* ---------- 项目实践区域 ---------- */
.projects-content {
    text-align: center;
    padding: 60px 0;
}

.projects-text {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    color: var(--text-gray);
}

/* ---------- 联系区域 ---------- */
.contact-wrapper {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-info {
    display: inline-block;
    text-align: left;
}

.contact-info .section-title {
    text-align: center;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-top: 30px;
}

.contact-item i {
    font-size: 1.2rem;
    color: var(--text-gray);
}

.contact-item .label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-gray);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 5px;
}

.contact-item .value {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    color: var(--text-white);
}

.contact-item .value:hover {
    color: var(--text-gray);
}

/* ---------- 页脚 ---------- */
.footer-section {
    background: var(--bg-dark);
    padding: 60px 0;
    border-top: 1px solid var(--border-color);
}

.footer-text {
    font-size: 0.8rem;
    color: var(--text-gray);
    letter-spacing: 1px;
    text-align: center;
}

.tech-support {
    font-size: 0.85rem !important;
    color: var(--text-muted) !important;
    margin-top: 10px;
    text-align: center;
}

.tech-support a {
    color: var(--text-white);
    transition: color 0.3s;
}

.tech-support a:hover {
    color: var(--text-gray);
    text-decoration: underline;
}

/* ---------- 回到顶部 ---------- */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--bg-dark-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-white);
    font-size: 1rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--text-white);
    color: var(--bg-dark);
}

/* ---------- 进度条 ---------- */
#progressBar {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 2px;
    background: linear-gradient(90deg, var(--text-gray), var(--text-white));
    z-index: 1001;
    transition: width 0.1s linear;
}

/* ---------- 动画 ---------- */
.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

.fade-in-up.delay-1 { transition-delay: 0.1s; }
.fade-in-up.delay-2 { transition-delay: 0.2s; }
.fade-in-up.delay-3 { transition-delay: 0.3s; }
.fade-in-up.delay-4 { transition-delay: 0.4s; }

/* ---------- 响应式 ---------- */
@media (max-width: 992px) {
    .nav-menu {
        position: fixed;
        top: 80px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 80px);
        background: var(--bg-dark);
        flex-direction: column;
        align-items: center;
        justify-content: flex-start;
        padding-top: 60px;
        gap: 40px;
        transition: left 0.3s ease;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: block;
    }

    .study-grid {
        grid-template-columns: 1fr;
    }

    .photo-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 25px;
    }

    .nav-container {
        padding: 0 25px;
    }

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

    .photo-grid {
        grid-template-columns: 1fr;
    }

    .contact-item {
        flex-direction: column;
        text-align: center;
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        letter-spacing: 4px;
    }

    .hero-tags {
        font-size: 0.7rem;
    }

    .study-card {
        padding: 30px 20px;
    }

    .timeline-content {
        flex-direction: column;
        gap: 5px;
    }
}