/* ===== 变量定义 ===== */
:root {
    --primary: #1E3A8A;
    --primary-light: #2563EB;
    --accent: #F97316;
    --accent-light: #FB923C;
    --gradient-start: #6366F1;
    --gradient-end: #8B5CF6;
    --dark: #0F172A;
    --darker: #0B1120;
    --light: #F8FAFC;
    --white: #FFFFFF;
    --gray-light: #F1F5F9;
    --gray: #E2E8F0;
    --text: #1E293B;
    --text-light: #475569;
    --text-muted: #94A3B8;
    --shadow: 0 4px 20px rgba(0,0,0,0.08);
    --shadow-hover: 0 12px 40px rgba(0,0,0,0.14);
    --radius: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== 基础重置 ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
    font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', sans-serif;
    color: var(--text);
    line-height: 1.7;
    background: var(--white);
    -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; }
a { text-decoration: none; }
ul { list-style: none; }

/* ===== 通用 ===== */
.container { max-width: 1100px; margin: 0 auto; padding: 0 32px; }
.section { padding: 96px 0; }
.section-gray { background: var(--light); }
.section-title {
    font-size: 40px; font-weight: 800; text-align: center;
    color: var(--primary); margin-bottom: 16px;
    letter-spacing: -0.5px;
}
.section-title::after {
    content: ''; display: block; width: 60px; height: 4px;
    background: var(--accent); border-radius: 2px; margin: 12px auto 0;
}
.section-sub {
    text-align: center; color: var(--text-light); font-size: 17px;
    margin-bottom: 56px; max-width: 600px; margin-left: auto; margin-right: auto;
}
.section-sub a { color: var(--accent); border-bottom: 1px solid var(--accent); }
.section-sub a:hover { color: var(--primary); border-color: var(--primary); }

/* 入场动画 */
.fade-in { opacity: 0; transform: translateY(30px); transition: opacity 0.7s ease, transform 0.7s ease; }
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* ===== 导航栏 ===== */
nav {
    position: fixed; top: 0; width: 100%; z-index: 1000;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(12px);
    transition: var(--transition);
}
nav.scrolled { box-shadow: 0 4px 30px rgba(0,0,0,0.25); }
.nav-inner {
    max-width: 1200px; margin: 0 auto;
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 32px; height: 72px;
}
.logo {
    font-size: 22px; font-weight: 800;
    color: var(--gradient-start); letter-spacing: 2px;
}
.nav-links { display: flex; gap: 4px; }
.nav-links a {
    color: #94A3B8; padding: 8px 16px; border-radius: 8px;
    font-size: 15px; transition: var(--transition);
}
.nav-links a:hover, .nav-links a.active { color: var(--white); background: rgba(99,102,241,0.3); }
.btn-resume {
    background: var(--accent); color: var(--white);
    padding: 9px 22px; border-radius: 50px;
    font-size: 14px; font-weight: 600; transition: var(--transition);
    box-shadow: 0 4px 14px rgba(249,115,22,0.35);
}
.btn-resume:hover { background: var(--accent-light); transform: translateY(-1px); box-shadow: 0 6px 20px rgba(249,115,22,0.45); }

/* 汉堡菜单 */
.hamburger {
    display: none; background: none; border: none; cursor: pointer;
    flex-direction: column; gap: 5px; padding: 8px;
}
.hamburger span {
    display: block; width: 24px; height: 2px;
    background: var(--white); border-radius: 2px;
    transition: var(--transition);
}
.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.mobile-menu {
    display: none; background: var(--dark);
    padding: 16px 24px 24px;
    border-top: 1px solid rgba(255,255,255,0.08);
}
.mobile-menu.active { display: block; }
.mobile-menu ul { display: flex; flex-direction: column; gap: 4px; }
.mobile-menu a {
    display: block; color: #94A3B8; padding: 12px 16px;
    border-radius: 10px; font-size: 16px; transition: var(--transition);
}
.mobile-menu a:hover { color: var(--white); background: rgba(99,102,241,0.25); }

/* ===== Hero 区 ===== */
.hero {
    min-height: 100vh; position: relative;
    display: flex; flex-direction: column;
    align-items: center; justify-content: center;
    padding: 100px 32px 60px; text-align: center;
    overflow: hidden;
}
.hero-bg {
    position: absolute; inset: 0; z-index: -1;
    background: linear-gradient(135deg, var(--dark) 0%, #1a1040 50%, #0f2040 100%);
}
.hero-bg::before {
    content: ''; position: absolute; inset: 0;
    background: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(99,102,241,0.2) 0%, transparent 70%),
                radial-gradient(ellipse 60% 40% at 80% 80%, rgba(139,92,246,0.15) 0%, transparent 60%);
}
.hero-bg::after {
    content: ''; position: absolute; inset: 0;
    background-image:
        radial-gradient(circle, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 40px 40px;
}

.hero-content h1 {
    font-size: 72px; font-weight: 900; color: var(--white);
    letter-spacing: -2px; margin-bottom: 8px;
    background: linear-gradient(135deg, var(--white) 0%, rgba(255,255,255,0.85) 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-greeting { color: var(--text-muted); font-size: 18px; margin-bottom: 8px; }
.hero-tagline {
    font-size: 20px; color: var(--gradient-start);
    font-weight: 600; margin-bottom: 16px;
    letter-spacing: 1px;
}
.hero-desc {
    color: #64748B; font-size: 17px; max-width: 560px;
    margin: 0 auto 40px; line-height: 1.8;
}
.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn-primary {
    background: var(--accent); color: var(--white);
    padding: 14px 36px; border-radius: 50px;
    font-size: 16px; font-weight: 700;
    transition: var(--transition);
    box-shadow: 0 4px 20px rgba(249,115,22,0.4);
}
.btn-primary:hover { background: var(--accent-light); transform: translateY(-2px); box-shadow: 0 8px 28px rgba(249,115,22,0.5); }
.btn-secondary {
    border: 2px solid rgba(255,255,255,0.2); color: var(--white);
    padding: 14px 36px; border-radius: 50px;
    font-size: 16px; font-weight: 600;
    transition: var(--transition);
}
.btn-secondary:hover { border-color: var(--gradient-start); background: rgba(99,102,241,0.15); transform: translateY(-2px); }

/* 核心优势卡片 */
.hero-cards {
    display: grid; grid-template-columns: repeat(3, 1fr);
    gap: 20px; max-width: 760px; margin-top: 64px;
}
.hero-card {
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.1);
    backdrop-filter: blur(10px);
    border-radius: 16px; padding: 28px 24px;
    text-align: center; color: var(--white);
    transition: var(--transition);
}
.hero-card:hover { background: rgba(255,255,255,0.1); transform: translateY(-4px); }
.card-icon { font-size: 32px; display: block; margin-bottom: 12px; }
.hero-card h3 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.hero-card p { font-size: 13px; color: #64748B; }

/* ===== 关于我 ===== */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: start; }
.about-text h3 { font-size: 22px; color: var(--primary); margin-bottom: 20px; font-weight: 700; }
.about-text p { color: var(--text-light); margin-bottom: 16px; font-size: 16px; line-height: 1.8; }
.about-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 24px; }
.tag-item {
    background: #EEF2FF; color: var(--primary-light);
    padding: 6px 16px; border-radius: 50px;
    font-size: 13px; font-weight: 600;
}
.about-values { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.value-card {
    background: var(--light); border-radius: 14px;
    padding: 24px 20px; border: 1px solid var(--gray);
    transition: var(--transition);
}
.value-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--gradient-start); }
.value-card span { font-size: 28px; display: block; margin-bottom: 8px; }
.value-card h4 { font-size: 15px; font-weight: 700; color: var(--text); margin-bottom: 6px; }
.value-card p { font-size: 13px; color: var(--text-light); }

/* ===== 项目经历 ===== */
.projects-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 28px; }
.project-card {
    background: var(--white); border-radius: var(--radius);
    padding: 32px; border: 1px solid var(--gray);
    transition: var(--transition);
    display: flex; flex-direction: column;
}
.project-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); border-color: var(--accent); }
.project-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 14px; }
.project-header h3 { font-size: 19px; font-weight: 700; color: var(--text); }
.project-status { font-size: 12px; padding: 3px 12px; border-radius: 50px; font-weight: 600; background: #DCFCE7; color: #16A34A; }
.project-status-soon { background: #FEF9C3; color: #CA8A04; }
.project-card p { color: var(--text-light); font-size: 15px; margin-bottom: 16px; line-height: 1.7; flex-grow: 1; }
.project-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.tech-tag { background: var(--gray-light); color: var(--text-light); padding: 4px 12px; border-radius: 6px; font-size: 12px; font-weight: 600; }
.project-points { margin-bottom: 20px; }
.project-points li { color: var(--text-light); font-size: 14px; padding: 4px 0 4px 20px; position: relative; }
.project-points li::before { content: '→'; position: absolute; left: 0; color: var(--accent); font-weight: 700; }
.project-link { color: var(--primary-light); font-size: 14px; font-weight: 600; border-bottom: 1px solid var(--primary-light); padding-bottom: 2px; align-self: flex-start; transition: var(--transition); }
.project-link:hover { color: var(--accent); border-color: var(--accent); }
.project-card-placeholder { background: var(--gray-light); border-style: dashed; opacity: 0.8; }

/* ===== 时间线 ===== */
.timeline { max-width: 700px; margin: 0 auto; position: relative; }
.timeline::before {
    content: ''; position: absolute; left: 108px; top: 0; bottom: 0;
    width: 2px; background: linear-gradient(to bottom, var(--gradient-start), var(--gradient-end));
}
.timeline-item { display: grid; grid-template-columns: 100px 1fr; gap: 28px; margin-bottom: 40px; position: relative; }
.timeline-dot {
    width: 14px; height: 14px; border-radius: 50%;
    background: var(--gradient-start); border: 3px solid var(--white);
    box-shadow: 0 0 0 2px var(--gradient-start);
    margin-top: 4px; position: relative; z-index: 1;
}
.timeline-dot-future { background: var(--gray); box-shadow: none; border-color: var(--gray); }
.timeline-date { font-size: 14px; font-weight: 700; color: var(--primary); padding-top: 4px; text-align: right; }
.timeline-item-future .timeline-date { color: var(--text-muted); }
.timeline-content {
    background: var(--white); border-radius: 14px; padding: 24px;
    border: 1px solid var(--gray); box-shadow: var(--shadow);
    transition: var(--transition);
}
.timeline-content:hover { transform: translateY(-2px); box-shadow: var(--shadow-hover); border-color: var(--gradient-start); }
.timeline-item-future .timeline-content { background: var(--light); border-style: dashed; }
.timeline-content h3 { font-size: 18px; font-weight: 700; color: var(--text); margin-bottom: 4px; }
.timeline-sub { font-size: 13px; color: var(--accent); font-weight: 600; margin-bottom: 10px; }
.timeline-content p { font-size: 15px; color: var(--text-light); margin-bottom: 12px; }
.timeline-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.timeline-tags span { background: var(--gray-light); color: var(--text-light); padding: 3px 10px; border-radius: 4px; font-size: 12px; }

/* ===== 技能专长 ===== */
.skills-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }
.skill-category {
    background: var(--white); border-radius: var(--radius);
    padding: 28px; border: 1px solid var(--gray);
    transition: var(--transition);
}
.skill-category:hover { box-shadow: var(--shadow); border-color: var(--gradient-start); }
.skill-category h3 { font-size: 17px; font-weight: 700; color: var(--text); margin-bottom: 20px; }
.skill-category h3 span { margin-right: 8px; }
.skill-list { display: flex; flex-direction: column; gap: 18px; }
.skill-item { }
.skill-header { display: flex; justify-content: space-between; font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 8px; }
.skill-header span:last-child { color: var(--text-muted); font-weight: 400; }
.skill-bar { background: var(--gray-light); border-radius: 10px; height: 8px; overflow: hidden; }
.skill-fill {
    height: 100%; border-radius: 10px; width: 0;
    background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
    transition: width 0.9s cubic-bezier(0.4, 0, 0.2, 1);
}
.skill-tags { display: flex; flex-wrap: wrap; gap: 10px; }
.skill-tags span {
    background: var(--gray-light); color: var(--text-light);
    padding: 7px 16px; border-radius: 8px;
    font-size: 14px; font-weight: 500; transition: var(--transition);
    border: 1px solid transparent;
}
.skill-tags span:hover { background: #EEF2FF; color: var(--primary-light); border-color: var(--primary-light); }

/* ===== 联系方式 ===== */
.contact-grid { display: grid; grid-template-columns: 340px 1fr; gap: 48px; align-items: start; }
.contact-info { display: flex; flex-direction: column; gap: 20px; }
.contact-item-card {
    background: var(--white); border-radius: 14px; padding: 24px;
    border: 1px solid var(--gray); display: flex; gap: 20px;
    align-items: flex-start; transition: var(--transition);
}
.contact-item-card:hover { box-shadow: var(--shadow); border-color: var(--gradient-start); }
.contact-icon { font-size: 32px; }
.contact-item-card h4 { font-size: 14px; font-weight: 700; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 4px; }
.contact-item-card p { font-size: 16px; color: var(--text); font-weight: 600; margin-bottom: 10px; }
.copy-btn, .contact-link-btn {
    font-size: 13px; font-weight: 600; padding: 6px 14px;
    border-radius: 6px; border: none; cursor: pointer;
    transition: var(--transition);
}
.copy-btn { background: var(--gray-light); color: var(--text-light); }
.copy-btn:hover { background: var(--accent); color: var(--white); }
.contact-link-btn { background: #EEF2FF; color: var(--primary-light); text-decoration: none; display: inline-block; }
.contact-link-btn:hover { background: var(--primary-light); color: var(--white); }

.contact-form-area h3 { font-size: 22px; font-weight: 700; color: var(--text); margin-bottom: 8px; }
.form-note { font-size: 13px; color: var(--text-muted); margin-bottom: 20px; }
.contact-form { display: flex; flex-direction: column; gap: 16px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.contact-form input, .contact-form textarea {
    width: 100%; padding: 14px 18px; border-radius: 10px;
    border: 2px solid var(--gray); font-size: 15px; font-family: inherit;
    transition: var(--transition); background: var(--white); color: var(--text);
    resize: vertical;
}
.contact-form input:focus, .contact-form textarea:focus {
    outline: none; border-color: var(--gradient-start);
    box-shadow: 0 0 0 3px rgba(99,102,241,0.15);
}
.contact-form input::placeholder, .contact-form textarea::placeholder { color: var(--text-muted); }
.btn-submit {
    background: var(--accent); color: var(--white);
    padding: 15px 32px; border-radius: 10px;
    font-size: 16px; font-weight: 700; border: none; cursor: pointer;
    transition: var(--transition); box-shadow: 0 4px 14px rgba(249,115,22,0.3);
    align-self: flex-start;
}
.btn-submit:hover { background: var(--accent-light); transform: translateY(-1px); }
.btn-submit:active { transform: scale(0.98); }

/* ===== 页脚 ===== */
footer { background: var(--dark); color: var(--text-muted); padding: 48px 32px; text-align: center; }
.footer-inner { max-width: 800px; margin: 0 auto; }
.footer-logo { font-size: 24px; font-weight: 800; color: var(--gradient-start); letter-spacing: 2px; margin-bottom: 12px; }
.footer-inner p { font-size: 14px; margin-bottom: 20px; }
.footer-links { display: flex; justify-content: center; gap: 24px; flex-wrap: wrap; }
.footer-links a { color: var(--text-muted); font-size: 14px; transition: var(--transition); }
.footer-links a:hover { color: var(--white); }

/* ===== 滚动条 ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--light); }
::-webkit-scrollbar-thumb { background: var(--gradient-start); border-radius: 3px; }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .about-grid { grid-template-columns: 1fr; gap: 40px; }
    .about-values { grid-template-columns: 1fr 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
    .nav-links, .btn-resume { display: none; }
    .hamburger { display: flex; }
    .hero-content h1 { font-size: 44px; letter-spacing: -1px; }
    .hero-tagline { font-size: 16px; }
    .hero-cards { grid-template-columns: 1fr; max-width: 320px; gap: 14px; }
    .hero-card { padding: 20px; }
    .section { padding: 64px 0; }
    .section-title { font-size: 30px; }
    .skills-grid { grid-template-columns: 1fr; }
    .about-values { grid-template-columns: 1fr; }
    .form-row { grid-template-columns: 1fr; }
    .timeline::before { left: 0; }
    .timeline-item { grid-template-columns: 1fr; gap: 8px; }
    .timeline-date { text-align: left; padding-left: 28px; }
    .timeline-dot { position: absolute; left: -7px; }
}
@media (max-width: 480px) {
    .hero-content h1 { font-size: 36px; }
    .hero-btns { flex-direction: column; align-items: center; }
    .btn-primary, .btn-secondary { width: 100%; text-align: center; }
}