/* ═══════════════════════════════════════════════════════
   Apple-inspired design system
   单一蓝色强调 · SF 系统字体 · 玻璃拟态 · 大圆角 · 留白
   ═══════════════════════════════════════════════════════ */

:root {
  --bg: #f5f5f7;
  --bg-elevated: #ffffff;
  --text: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #86868b;
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --link-accent: #06c;
  --card-bg: #ffffff;
  --nav-bg: rgba(251, 251, 253, 0.72);
  --border: rgba(0, 0, 0, 0.1);
  --hairline: rgba(0, 0, 0, 0.06);
  --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.06);
  --shadow-color: rgba(0, 0, 0, 0.12);
  --glow: rgba(0, 113, 227, 0.2);
  --focus-ring: rgba(0, 113, 227, 0.4);
  --hero-glow-1: rgba(0, 113, 227, 0.22);
  --hero-glow-2: rgba(64, 156, 255, 0.16);
  --radius: 18px;
  --radius-sm: 12px;
  --font: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text',
          'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue',
          'Segoe UI', Roboto, Arial, sans-serif;
  --max-w: 980px;
  --max-w-narrow: 680px;
  --nav-h: 48px;
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-out: cubic-bezier(0.33, 1, 0.68, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

[data-theme="dark"] {
  --bg: #000000;
  --bg-elevated: #161617;
  --text: #f5f5f7;
  --text-secondary: #a1a1a6;
  --text-tertiary: #86868b;
  --accent: #2997ff;
  --accent-hover: #47a8ff;
  --link-accent: #2997ff;
  --card-bg: #1c1c1e;
  --nav-bg: rgba(0, 0, 0, 0.72);
  --border: rgba(255, 255, 255, 0.14);
  --hairline: rgba(255, 255, 255, 0.08);
  --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.35);
  --shadow-color: rgba(0, 0, 0, 0.55);
  --glow: rgba(41, 151, 255, 0.22);
  --focus-ring: rgba(41, 151, 255, 0.4);
  --hero-glow-1: rgba(41, 151, 255, 0.2);
  --hero-glow-2: rgba(88, 200, 255, 0.12);
}

*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  transition: background 0.4s var(--ease), color 0.4s var(--ease);
  overflow-x: hidden;
}

::selection {
  background: var(--accent);
  color: #fff;
}

a {
  color: var(--link-accent);
  text-decoration: none;
  transition: color 0.2s ease;
}

:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 2px;
}

/* ─── Cursor Glow ─── */
#cursorGlow {
  position: fixed;
  top: 0;
  left: 0;
  width: 360px;
  height: 360px;
  border-radius: 50%;
  pointer-events: none;
  z-index: 9999;
  background: radial-gradient(circle, var(--glow) 0%, transparent 70%);
  transform: translate(-50%, -50%);
  opacity: 0;
  transition: opacity 0.6s ease;
  will-change: transform;
}

#cursorGlow.active {
  opacity: 1;
}

/* ─── Scroll Progress ─── */
#scrollProgress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--hero-glow-2));
  z-index: 101;
  width: 0%;
  transition: width 0.1s linear;
}

/* ─── Navbar ─── */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  background: var(--nav-bg);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--hairline);
  z-index: 100;
  transition: transform 0.5s var(--ease), background 0.4s var(--ease), border-color 0.4s var(--ease);
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  position: relative;
}

.nav-logo {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text);
}

.nav-logo:hover {
  color: var(--text);
}

.nav-links {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 36px;
}

.nav-link {
  font-size: 13px;
  font-weight: 400;
  letter-spacing: 0.01em;
  color: var(--text-secondary);
  padding: 4px 0;
  transition: color 0.2s var(--ease);
}

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

.nav-link.active {
  color: var(--link-accent);
}

.nav-actions {
  display: flex;
  align-items: center;
}

/* ─── Theme Toggle ─── */
.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-secondary);
  padding: 6px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.2s ease, background 0.2s ease, transform 0.3s var(--ease-spring);
}

.theme-toggle:hover {
  color: var(--text);
  background: var(--hairline);
}

.theme-toggle.spin svg {
  animation: spinIcon 0.5s var(--ease-spring);
}

@keyframes spinIcon {
  0% { transform: rotate(0deg) scale(0.8); opacity: 0; }
  50% { transform: rotate(180deg) scale(1.1); }
  100% { transform: rotate(360deg) scale(1); opacity: 1; }
}

[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
.sun-icon { display: none; }
.moon-icon { display: block; }

/* ─── Hero ─── */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 120px 24px 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
}

.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  will-change: transform;
}

.hero-glow--1 {
  width: 520px;
  height: 520px;
  background: var(--hero-glow-1);
  top: 8%;
  right: 4%;
}

.hero-glow--2 {
  width: 420px;
  height: 420px;
  background: var(--hero-glow-2);
  bottom: 4%;
  left: 0;
}

/* 光球的位置由 js/main.js 中的鼠标视差 + 缓动漂浮驱动（tickGlows） */

.hero-content {
  max-width: var(--max-w-narrow);
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: clamp(44px, 8vw, 76px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: 16px;
  opacity: 0;
  animation: fadeUp 0.9s var(--ease-out) 0.15s forwards;
}

.hero-subtitle {
  font-size: clamp(20px, 3.5vw, 26px);
  font-weight: 600;
  color: var(--text-secondary);
  letter-spacing: -0.01em;
  margin-bottom: 18px;
  opacity: 0;
  animation: fadeUp 0.9s var(--ease-out) 0.4s forwards;
}

.hero-desc {
  font-size: 16px;
  color: var(--text-tertiary);
  line-height: 1.7;
  margin-bottom: 36px;
  opacity: 0;
  animation: fadeUp 0.9s var(--ease-out) 0.65s forwards;
}

@keyframes fadeUp {
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  to { opacity: 1; }
}

.hero-title,
.hero-subtitle,
.hero-desc,
.hero-cta-row {
  transform: translateY(18px);
}

.hero-cta-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 28px;
  opacity: 0;
  animation: fadeUp 0.9s var(--ease-out) 0.9s forwards;
}

/* ─── Buttons ─── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 400;
  cursor: pointer;
  border: none;
  transition: transform 0.15s ease, box-shadow 0.3s ease, background 0.2s ease, color 0.2s ease;
}

.btn-primary {
  padding: 13px 30px;
  color: #fff;
  background: var(--accent);
  border-radius: 980px;
  will-change: transform;
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
  box-shadow: 0 6px 24px var(--glow);
}

.btn-primary:active {
  transform: scale(0.96);
}

.btn-link {
  color: var(--link-accent);
  font-size: 17px;
  padding: 8px 2px;
}

.btn-link .chev {
  display: inline-block;
  margin-left: 4px;
  transition: transform 0.3s var(--ease-out);
}

.btn-link:hover {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.btn-link:hover .chev {
  transform: translateX(3px);
}

/* ─── Scroll Indicator ─── */
.scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  opacity: 0;
  animation: fadeIn 0.9s var(--ease-out) 1.6s forwards;
  z-index: 1;
}

.scroll-indicator span {
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  font-weight: 500;
}

.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--text-tertiary), transparent);
  animation: scrollPulse 2.2s var(--ease) infinite;
}

@keyframes scrollPulse {
  0%, 100% { transform: scaleY(0.4); opacity: 0.2; }
  50% { transform: scaleY(1); opacity: 1; }
}

/* ─── Sections ─── */
.section {
  padding: 130px 24px;
  position: relative;
}

.posts {
  background: var(--bg-elevated);
  transition: background 0.4s var(--ease);
}

.about {
  background: var(--bg);
}

.contact {
  background: var(--bg-elevated);
  transition: background 0.4s var(--ease);
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.9s var(--ease-out), transform 0.9s var(--ease-out);
}

.section-reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

.eyebrow {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: 10px;
}

.section-title {
  font-size: clamp(32px, 4.5vw, 44px);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.1;
  margin-bottom: 12px;
}

.section-desc {
  font-size: 17px;
  color: var(--text-secondary);
}

/* ─── Posts ─── */
.posts-grid {
  max-width: var(--max-w-narrow);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.post-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  cursor: pointer;
  position: relative;
  will-change: transform;
  box-shadow: var(--shadow-card);
  transition: transform 0.6s var(--ease-out), opacity 0.6s var(--ease-out),
              box-shadow 0.5s var(--ease-out), border-color 0.3s ease;
}

.post-card:hover {
  transform: translateY(-6px);
  border-color: var(--border);
  box-shadow: var(--shadow-x, 0px) var(--shadow-y, 18px) 48px var(--shadow-color);
}

.post-card-body {
  position: relative;
  z-index: 1;
}

.post-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--text-tertiary);
  text-transform: uppercase;
  margin-bottom: 12px;
}

.post-title {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.3;
  margin-bottom: 10px;
  color: var(--text);
}

.post-card:hover .post-title {
  color: var(--accent);
}

.post-excerpt {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}

.post-meta {
  display: flex;
  gap: 16px;
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ─── About ─── */
.about-inner {
  max-width: var(--max-w-narrow);
  margin: 0 auto;
  display: flex;
  gap: 56px;
  align-items: center;
}

.about-avatar {
  flex-shrink: 0;
}

.avatar-img {
  width: 128px;
  height: 128px;
  border-radius: 50%;
  object-fit: cover;
  display: block;
  box-shadow: var(--shadow-card);
  transition: transform 0.4s var(--ease-spring);
}

.avatar-img:hover {
  transform: scale(1.04);
}

.stats-row {
  display: flex;
  gap: 32px;
  margin-bottom: 24px;
}

.stat {
  font-size: 13px;
  color: var(--text-tertiary);
}

.stat strong {
  font-size: 24px;
  font-weight: 700;
  color: var(--text);
  display: block;
  letter-spacing: -0.02em;
  margin-bottom: 2px;
}

.about-text p {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}

.about-social {
  display: flex;
  gap: 16px;
  margin-top: 28px;
}

.social-link {
  font-size: 14px;
  font-weight: 400;
  color: var(--link-accent);
  padding: 8px 20px;
  border: 1px solid var(--border);
  border-radius: 980px;
  transition: background 0.3s var(--ease-out), color 0.3s var(--ease-out),
              border-color 0.3s var(--ease-out), transform 0.2s var(--ease-spring);
}

.social-link:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  transform: translateY(-2px);
}

/* ─── Contact ─── */
.contact-form {
  max-width: 520px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.form-group {
  position: relative;
}

.form-input {
  width: 100%;
  padding: 20px 18px 8px;
  font-family: var(--font);
  font-size: 16px;
  color: var(--text);
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--focus-ring);
}

.form-textarea {
  resize: vertical;
  min-height: 110px;
  padding-top: 26px;
}

.form-label {
  position: absolute;
  left: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 16px;
  color: var(--text-tertiary);
  pointer-events: none;
  transition: all 0.25s var(--ease-out);
}

.form-textarea ~ .form-label {
  top: 20px;
  transform: none;
}

.form-input:focus ~ .form-label,
.form-input:not(:placeholder-shown) ~ .form-label {
  top: 10px;
  font-size: 11px;
  color: var(--accent);
}

.form-textarea:focus ~ .form-label,
.form-textarea:not(:placeholder-shown) ~ .form-label {
  top: 10px;
  font-size: 11px;
  color: var(--accent);
}

.form-submit {
  padding: 14px 36px;
  font-family: var(--font);
  font-size: 16px;
  font-weight: 400;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: 980px;
  cursor: pointer;
  align-self: flex-start;
  transition: background 0.2s ease, transform 0.2s var(--ease-spring),
              box-shadow 0.3s ease;
}

.form-submit span {
  position: relative;
  z-index: 1;
}

.form-submit:hover {
  background: var(--accent-hover);
  box-shadow: 0 6px 24px var(--glow);
}

.form-submit:active {
  transform: scale(0.96);
}

/* ─── Footer ─── */
.footer {
  padding: 48px 24px;
  text-align: center;
  border-top: 1px solid var(--hairline);
}

.footer-inner {
  max-width: var(--max-w-narrow);
  margin: 0 auto;
}

.footer p {
  font-size: 12px;
  color: var(--text-tertiary);
  letter-spacing: 0.02em;
}

/* ─── Post Card Entrance ─── */
.post-card {
  opacity: 0;
  transform: translateY(24px) scale(0.98);
}

.post-card.visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

/* ─── Blog Modal ─── */
.blog-modal {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  flex-direction: column;
  opacity: 0;
  transform: translateY(28px);
  pointer-events: none;
  transition: opacity 0.5s var(--ease-out), transform 0.5s var(--ease-out);
}

.blog-modal.active {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.blog-modal-backdrop {
  position: absolute;
  inset: 0;
  background: var(--bg);
  z-index: 0;
}

.blog-modal-container {
  position: relative;
  z-index: 1;
  flex: 1;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.blog-modal-header {
  position: sticky;
  top: 0;
  z-index: 10;
  padding: 14px 24px;
  background: var(--nav-bg);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--hairline);
}

.blog-modal-close {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 400;
  color: var(--link-accent);
  background: none;
  border: none;
  border-radius: 980px;
  cursor: pointer;
  transition: background 0.2s var(--ease-out), transform 0.2s var(--ease-spring);
  font-family: var(--font);
}

.blog-modal-close:hover {
  background: var(--hairline);
}

.blog-article {
  max-width: var(--max-w-narrow);
  margin: 0 auto;
  padding: 56px 24px 96px;
}

.blog-article-title {
  font-size: clamp(32px, 4.5vw, 44px);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.15;
  margin-bottom: 40px;
  color: var(--text);
}

/* ─── Blog Article Body (rendered markdown) ─── */
.blog-article-body {
  font-size: 17px;
  line-height: 1.8;
  color: var(--text-secondary);
  overflow-wrap: break-word;
}

.blog-article-body h1,
.blog-article-body h2,
.blog-article-body h3,
.blog-article-body h4,
.blog-article-body h5,
.blog-article-body h6 {
  margin-top: 1.6em;
  margin-bottom: 0.5em;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text);
  line-height: 1.3;
}

.blog-article-body h1 { font-size: 1.7em; }
.blog-article-body h2 { font-size: 1.4em; }
.blog-article-body h3 { font-size: 1.2em; }

.blog-article-body p {
  margin-bottom: 1.2em;
}

.blog-article-body ul,
.blog-article-body ol {
  margin-bottom: 1.2em;
  padding-left: 1.6em;
}

.blog-article-body li {
  margin-bottom: 0.4em;
}

.blog-article-body blockquote {
  border-left: 3px solid var(--accent);
  margin: 1.6em 0;
  padding: 12px 24px;
  background: var(--bg-elevated);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-secondary);
}

.blog-article-body blockquote p {
  margin-bottom: 0;
}

.blog-article-body code {
  font-family: 'SF Mono', ui-monospace, 'Cascadia Mono', 'Fira Code', Consolas, monospace;
  font-size: 0.9em;
  background: var(--bg-elevated);
  padding: 2px 6px;
  border-radius: 5px;
  border: 1px solid var(--border);
}

.blog-article-body pre {
  margin: 1.4em 0;
  padding: 20px 24px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow-x: auto;
}

.blog-article-body pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: 14px;
  line-height: 1.7;
}

.blog-article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.4em 0;
  font-size: 15px;
}

.blog-article-body th,
.blog-article-body td {
  padding: 12px 16px;
  border: 1px solid var(--border);
  text-align: left;
}

.blog-article-body th {
  background: var(--bg-elevated);
  font-weight: 600;
  color: var(--text);
}

.blog-article-body hr {
  border: none;
  border-top: 1px solid var(--hairline);
  margin: 2.5em 0;
}

.blog-article-body a {
  color: var(--link-accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.blog-article-body a:hover {
  color: var(--accent);
}

.blog-article-body img {
  max-width: 100%;
  border-radius: var(--radius-sm);
  margin: 1.4em 0;
}

body.modal-open {
  overflow: hidden;
}

/* ─── Posts Loading ─── */
.posts-loading {
  text-align: center;
  padding: 40px;
  color: var(--text-tertiary);
  font-size: 14px;
}

/* ─── Reduced Motion ─── */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ─── Responsive ─── */
@media (max-width: 760px) {
  .nav-links {
    gap: 22px;
  }
  .about-inner {
    flex-direction: column;
    text-align: center;
  }
  .stats-row {
    justify-content: center;
  }
  .about-social {
    justify-content: center;
  }
  .section {
    padding: 90px 20px;
  }
  .post-card {
    padding: 24px;
  }
  .hero-glow--1 {
    width: 380px;
    height: 380px;
  }
  .hero-glow--2 {
    width: 300px;
    height: 300px;
  }
}