@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700;800;900&family=DM+Mono:wght@400;500&display=swap');

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

/* ── Variables ── */
:root {
  --bg:        #F9F8F5;
  --bg2:       #F0EEE9;
  --surface:   #FFFFFF;
  --surface2:  #F5F4F1;
  --border:    #E8E5DC;
  --border2:   #D4D0C6;
  --text:      #1A1916;
  --text2:     #6B6860;
  --text3:     #9E9B94;
  --accent:    #C9963A;
  --accent-lt: #FDF7EC;
  --accent-hv: #A47830;
  --gold:      #B07828;
  --gold-lt:   #FDF0DC;
  --teal:      #0D9488;
  --teal-lt:   #EDFAF8;
  --purple:    #7C3AED;
  --purple-lt: #F5F0FF;
  --rose:      #E11D48;
  --rose-lt:   #FFF1F2;
  --green:     #16A34A;
  --red:       #DC2626;
  --font:      'Outfit','PingFang SC','Hiragino Sans GB','Microsoft YaHei','Noto Sans CJK SC',sans-serif;
  --mono:      'DM Mono','SF Mono','Consolas',monospace;
  --nav-h:     88px;
  --max-w:     1200px;
  --r:         10px;
  --r-lg:      16px;
  --shadow:    0 1px 2px rgba(0,0,0,.04), 0 4px 16px rgba(0,0,0,.05);
  --shadow-lg: 0 4px 8px rgba(0,0,0,.05), 0 16px 48px rgba(0,0,0,.08);
  --tr:        0.22s ease;
}
html[data-theme='dark'] {
  --bg:        #0D0B07;
  --bg2:       #121008;
  --surface:   #181510;
  --surface2:  #1D1B14;
  --border:    #2C291E;
  --border2:   #3A3828;
  --text:      #F0EEE6;
  --text2:     #8A8880;
  --text3:     #55534E;
  --accent:    #D4A848;
  --accent-lt: #1A1408;
  --accent-hv: #E8BC5C;
  --gold:      #C09038;
  --gold-lt:   #150F04;
  --teal:      #2DD4BF;
  --teal-lt:   #0A1C1A;
  --purple:    #A78BFA;
  --purple-lt: #1A1230;
  --rose:      #FB7185;
  --rose-lt:   #1C0810;
  --shadow:    0 1px 2px rgba(0,0,0,.4), 0 4px 16px rgba(0,0,0,.4);
  --shadow-lg: 0 4px 8px rgba(0,0,0,.4), 0 16px 48px rgba(0,0,0,.5);
}

/* ── Base ── */
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background var(--tr), color var(--tr);
  min-height: 100vh;
}
a { color: var(--accent); text-decoration: none; transition: color var(--tr); }
a:hover { color: var(--accent-hv); }
img { max-width: 100%; display: block; }
[id] { scroll-margin-top: calc(var(--nav-h) + 16px); }

/* ── Container ── */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }
.container-sm { max-width: 800px; margin: 0 auto; padding: 0 24px; }

/* ── Nav ── */
.navbar {
  position: sticky; top: 0; z-index: 100;
  height: var(--nav-h);
  background: rgba(249,248,245,.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  transition: background var(--tr), border-color var(--tr), box-shadow var(--tr);
}
html[data-theme='dark'] .navbar {
  background: rgba(13,11,7,.9);
}
.navbar.scrolled { box-shadow: var(--shadow); }
.nav-inner {
  max-width: var(--max-w); margin: 0 auto; padding: 0 24px;
  height: 100%; display: flex; align-items: center; gap: 8px;
}
.nav-logo {
  font-size: 22px; font-weight: 800; color: var(--text);
  letter-spacing: -0.5px; margin-right: 8px; flex-shrink: 0;
  display: flex; align-items: center; gap: 6px;
}
.nav-logo:hover { color: var(--text); }
.logo-mark {
  background: var(--accent); color: #fff;
  padding: 10px 20px; border-radius: 6px;
  font-size: 22px; font-weight: 700; letter-spacing: 0;
}
.logo-text { color: var(--text); }

.nav-links { display: flex; align-items: center; gap: 2px; flex: 1; }
.nav-links a {
  color: var(--text2); font-size: 18.5px; font-weight: 600;
  padding: 10px 14px; border-radius: 8px;
  transition: color var(--tr), background var(--tr);
  white-space: nowrap;
}
.nav-links a:hover { color: var(--text); background: var(--surface2); }
.nav-links a.active { color: var(--accent); }

/* Dropdown */
.nav-dropdown { position: relative; }
.nav-dropdown-toggle { display: flex; align-items: center; gap: 4px; cursor: pointer; }
.dropdown-arrow { font-size: 10px; transition: transform var(--tr); opacity: .6; }
.nav-dropdown:hover .dropdown-arrow { transform: rotate(180deg); }
.nav-dropdown-menu {
  position: absolute; top: calc(100% + 8px); left: 0;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r); box-shadow: var(--shadow-lg);
  min-width: 180px; padding: 6px;
  opacity: 0; visibility: hidden; transform: translateY(-6px);
  transition: opacity var(--tr), visibility var(--tr), transform var(--tr);
  pointer-events: none;
}
.nav-dropdown:hover .nav-dropdown-menu {
  opacity: 1; visibility: visible; transform: translateY(0); pointer-events: all;
}
.nav-dropdown-menu a {
  display: block; padding: 9px 14px; border-radius: 6px;
  font-size: 14px; color: var(--text2);
}
.nav-dropdown-menu a:hover { color: var(--text); background: var(--bg2); }

.nav-right { display: flex; align-items: center; gap: 8px; margin-left: auto; flex-shrink: 0; }

/* Theme toggle */
.theme-toggle {
  width: 36px; height: 36px; border-radius: 8px;
  border: 1px solid var(--border); background: var(--surface);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; font-size: 16px; transition: background var(--tr), border-color var(--tr);
  flex-shrink: 0;
}
.theme-toggle:hover { background: var(--surface2); }
.icon-sun, .icon-moon { line-height: 1; }
html[data-theme='dark'] .icon-sun { display: none; }
html:not([data-theme='dark']) .icon-moon { display: none; }

/* CTA button in nav */
.nav-cta {
  background: var(--accent); color: #fff !important;
  padding: 8px 16px !important; border-radius: 8px !important;
  font-weight: 600; font-size: 14px !important;
  transition: background var(--tr), transform var(--tr) !important;
}
.nav-cta:hover { background: var(--accent-hv) !important; color: #fff !important; transform: translateY(-1px); }

/* Mobile nav toggle */
.nav-toggle {
  display: none; flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 8px;
  width: 36px; height: 36px; justify-content: center; align-items: center;
}
.nav-toggle span {
  width: 20px; height: 2px; background: var(--text2);
  border-radius: 2px; transition: transform var(--tr), opacity var(--tr);
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.nav-mobile {
  display: none; background: var(--surface);
  border-top: 1px solid var(--border); padding: 12px 16px;
}
.nav-mobile.open { display: block; }
.nav-mobile a {
  display: block; padding: 11px 12px; color: var(--text2);
  font-size: 15px; font-weight: 500; border-radius: 8px;
  transition: color var(--tr), background var(--tr);
}
.nav-mobile a:hover { color: var(--text); background: var(--bg2); }
.mobile-section-title {
  font-size: 12px; font-weight: 700; color: var(--text3);
  text-transform: uppercase; letter-spacing: .8px;
  padding: 10px 12px 4px; margin-top: 4px;
}
.mobile-sub { padding-left: 24px !important; font-size: 14px !important; }
.mobile-cta {
  margin-top: 8px; background: var(--accent) !important;
  color: #fff !important; text-align: center !important;
  border-radius: 8px !important; font-weight: 600 !important;
}

/* ── Buttons ── */
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 11px 22px; border-radius: 10px;
  font-size: 15px; font-weight: 600; cursor: pointer;
  transition: background var(--tr), transform var(--tr), box-shadow var(--tr);
  border: none; text-decoration: none;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-hv); color: #fff; box-shadow: 0 4px 16px rgba(201,150,58,.35); }
.btn-outline {
  background: transparent; color: var(--accent);
  border: 1.5px solid var(--accent);
}
.btn-outline:hover { background: var(--accent-lt); }
.btn-sm { padding: 7px 14px; font-size: 13.5px; border-radius: 8px; }
.btn-lg { padding: 14px 28px; font-size: 16px; border-radius: 12px; }

/* ── Badges ── */
.badge {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 3px 10px; border-radius: 20px;
  font-size: 12px; font-weight: 600; letter-spacing: .3px;
}
.badge-free { background: var(--teal-lt); color: var(--teal); }
.badge-vip { background: var(--gold-lt); color: var(--gold); }
.badge-new { background: var(--accent-lt); color: var(--accent); }
.badge-soon { background: var(--surface2); color: var(--text3); }

/* ── Page Hero (small) ── */
.page-hero {
  background: var(--surface); border-bottom: 1px solid var(--border);
  padding: 48px 0 40px; text-align: center;
}
.page-hero h1 { font-size: 32px; font-weight: 800; letter-spacing: -0.5px; margin-bottom: 10px; }
.page-hero p { font-size: 16px; color: var(--text2); max-width: 540px; margin: 0 auto; }
.eyebrow {
  font-size: 12px; font-weight: 700; letter-spacing: 1.2px;
  text-transform: uppercase; color: var(--accent); margin-bottom: 10px;
}

/* ── Hero (homepage) ── */
.hero {
  padding: 112px 0 100px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  text-align: center;
  position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 0%, var(--accent-lt), transparent 70%);
  pointer-events: none;
}
html[data-theme='dark'] .hero::before {
  background: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(201,150,58,.07), transparent 70%);
}
.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 6px;
  background: var(--accent-lt); color: var(--accent);
  padding: 5px 14px; border-radius: 20px;
  font-size: 13px; font-weight: 600; margin-bottom: 28px;
  border: 1px solid rgba(201,150,58,.2);
}
.hero h1 {
  font-size: clamp(40px, 5vw, 62px);
  font-weight: 800; letter-spacing: -1px;
  line-height: 1.18; margin-bottom: 28px;
  color: var(--text);
}
.hero h1 em { font-style: normal; color: var(--accent); }
.hero-sub {
  font-size: 18px; color: var(--text2);
  max-width: 560px; margin: 0 auto 44px;
  line-height: 1.85;
}
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ── Stats Bar ── */
.stats-bar {
  background: var(--surface); border-bottom: 1px solid var(--border);
  padding: 0;
}
.stats-inner {
  display: flex; align-items: stretch; justify-content: center;
  max-width: var(--max-w); margin: 0 auto; padding: 0 24px;
  gap: 0;
}
.stat-item {
  flex: 1; text-align: center; padding: 20px 16px;
  border-right: 1px solid var(--border);
}
.stat-item:last-child { border-right: none; }
.stat-num { font-size: 26px; font-weight: 800; color: var(--accent); letter-spacing: -0.5px; }
.stat-label { font-size: 13px; color: var(--text2); margin-top: 2px; }

/* ── Section ── */
.section { padding: 72px 0; }
.section-sm { padding: 48px 0; }
.section-title { font-size: 26px; font-weight: 800; letter-spacing: -0.3px; margin-bottom: 8px; }
.section-sub { font-size: 15px; color: var(--text2); margin-bottom: 40px; }

/* ── Level Cards (homepage) ── */
.level-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.level-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: 24px;
  transition: transform var(--tr), box-shadow var(--tr), border-color var(--tr);
  cursor: pointer;
}
.level-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.level-card-num {
  font-size: 11px; font-weight: 700; letter-spacing: 1px;
  text-transform: uppercase; margin-bottom: 12px;
  display: flex; align-items: center; gap: 6px;
}
.level-card-num::before {
  content: ''; width: 8px; height: 8px; border-radius: 50%;
  background: currentColor; opacity: .7;
}
.lc-teal   { color: var(--teal); border-top: 3px solid var(--teal); }
.lc-blue   { color: var(--accent); border-top: 3px solid var(--accent); }
.lc-gold   { color: var(--gold); border-top: 3px solid var(--gold); }
.lc-purple { color: var(--purple); border-top: 3px solid var(--purple); }
.level-card h3 { font-size: 17px; font-weight: 700; margin-bottom: 8px; color: var(--text); }
.level-card p { font-size: 13.5px; color: var(--text2); line-height: 1.65; }
.level-card-meta {
  margin-top: 16px; padding-top: 14px; border-top: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  font-size: 12.5px; color: var(--text3);
}

/* ── Update Log ── */
.update-log { background: var(--surface2); border-radius: var(--r-lg); padding: 28px 32px; }
.update-log-title {
  font-size: 14px; font-weight: 700; color: var(--text3);
  text-transform: uppercase; letter-spacing: .8px; margin-bottom: 20px;
  display: flex; align-items: center; gap: 8px;
}
.update-log-title::after { content: ''; flex: 1; height: 1px; background: var(--border); }
.update-item {
  display: flex; align-items: baseline; gap: 14px;
  padding: 10px 0; border-bottom: 1px solid var(--border);
  font-size: 14px;
}
.update-item:last-child { border-bottom: none; padding-bottom: 0; }
.update-date { color: var(--text3); font-size: 12.5px; font-variant-numeric: tabular-nums; flex-shrink: 0; width: 50px; font-family: var(--mono); }
.update-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); flex-shrink: 0; margin-top: 7px; }
.update-text { color: var(--text2); flex: 1; }
.update-tag { font-size: 11.5px; padding: 2px 8px; border-radius: 12px; background: var(--accent-lt); color: var(--accent); flex-shrink: 0; }

/* ── Community CTA ── */
.community-cta {
  background: var(--accent); border-radius: var(--r-lg);
  padding: 48px 40px; text-align: center; color: #fff;
  position: relative; overflow: hidden;
}
.community-cta::before {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,.08) 0%, transparent 60%);
}
.community-cta h2 { font-size: 28px; font-weight: 800; margin-bottom: 10px; letter-spacing: -0.3px; }
.community-cta p { font-size: 16px; opacity: .85; margin-bottom: 28px; }
.btn-white { background: #fff; color: var(--accent); font-weight: 700; }
.btn-white:hover { background: #f0f4ff; color: var(--accent-hv); transform: translateY(-1px); }
.btn-white-outline { background: transparent; color: #fff; border: 1.5px solid rgba(255,255,255,.5); }
.btn-white-outline:hover { background: rgba(255,255,255,.1); color: #fff; }

/* ── Course Layout ── */
.course-layout {
  display: grid; grid-template-columns: 260px 1fr;
  max-width: var(--max-w); margin: 0 auto;
  padding: 0 24px; gap: 0; min-height: calc(100vh - var(--nav-h));
}
.sidebar {
  position: sticky; top: var(--nav-h);
  height: calc(100vh - var(--nav-h)); overflow-y: auto;
  padding: 28px 0 40px; border-right: 1px solid var(--border);
  scrollbar-width: thin; scrollbar-color: var(--border) transparent;
}
.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
.sidebar-inner { padding: 0 16px 0 0; }
.sidebar-title {
  font-size: 11px; font-weight: 700; letter-spacing: 1px;
  text-transform: uppercase; color: var(--text3); padding: 0 12px;
  margin-bottom: 12px;
}
.sidebar-link {
  display: flex; align-items: center; gap: 6px;
  padding: 7px 12px; border-radius: 7px; font-size: 13.5px;
  color: var(--text2); line-height: 1.4;
  transition: color var(--tr), background var(--tr);
}
.sidebar-link:hover { color: var(--text); background: var(--bg2); }
.sidebar-link.active { color: var(--accent); background: var(--accent-lt); font-weight: 600; }
.sidebar-section-title {
  display: flex; align-items: center; gap: 8px;
  font-size: 12px; font-weight: 700; color: var(--text2);
  padding: 14px 12px 6px; cursor: pointer; user-select: none;
  transition: color var(--tr);
}
.sidebar-section-title:hover { color: var(--text); }
.s-dot { width: 8px; height: 8px; border-radius: 50%; display: inline-block; flex-shrink: 0; }
.s-teal   { background: var(--teal); }
.s-blue   { background: var(--accent); }
.s-gold   { background: var(--gold); }
.s-purple { background: var(--purple); }
.s-rose   { background: var(--rose); }
.sidebar-arrow { margin-left: auto; font-size: 10px; opacity: .5; transition: transform var(--tr); }
.sidebar-section-title.collapsed .sidebar-arrow { transform: rotate(-90deg); }
.sidebar-section.collapsed { display: none; }
.sidebar-chapter {
  font-size: 11.5px; font-weight: 600; color: var(--text3);
  padding: 8px 12px 3px; text-transform: uppercase; letter-spacing: .5px;
}
.sidebar-cta { padding: 20px 0 0; }
.sidebar-cta .btn { width: 100%; justify-content: center; }

/* ── Course Content ── */
.course-content { padding: 40px 40px 80px; min-width: 0; }
.content-section { margin-bottom: 48px; }
.content-section h2 {
  font-size: 22px; font-weight: 700; margin-bottom: 16px; letter-spacing: -0.2px;
}
.overview-levels { display: flex; flex-direction: column; gap: 10px; margin-top: 16px; }
.ov-item {
  display: flex; align-items: center; gap: 12px;
  padding: 14px 16px; border-radius: 10px;
  border-left: 4px solid; background: var(--surface2);
}
.ov-teal { border-color: var(--teal); }
.ov-blue { border-color: var(--accent); }
.ov-gold { border-color: var(--gold); }
.ov-purple { border-color: var(--purple); }
.ov-rose   { border-color: var(--rose); }
.ov-label { font-weight: 700; font-size: 13px; min-width: 60px; }
.ov-text { font-size: 14px; color: var(--text2); }
.info-box {
  background: var(--accent-lt); border: 1px solid rgba(201,150,58,.2);
  border-radius: var(--r); padding: 20px 24px;
}
.info-box p { font-size: 14.5px; color: var(--text2); line-height: 1.7; margin-bottom: 8px; }
.info-box p:last-of-type { margin-bottom: 0; }
.info-box strong { color: var(--text); }

/* ── Level Sections ── */
.level-section { margin-bottom: 48px; }
.level-header {
  border-radius: var(--r-lg); padding: 24px 28px; margin-bottom: 20px;
  display: flex; align-items: flex-start; gap: 20px;
  border: 1px solid;
}
.lh-teal   { background: var(--teal-lt); border-color: rgba(13,148,136,.2); }
.lh-blue   { background: var(--accent-lt); border-color: rgba(201,150,58,.25); }
.lh-gold   { background: var(--gold-lt); border-color: rgba(176,120,40,.2); }
.lh-purple { background: var(--purple-lt); border-color: rgba(124,58,237,.2); }
.lh-rose   { background: var(--rose-lt);   border-color: rgba(225,29,72,.2); }
.level-num {
  font-size: 36px; font-weight: 900; opacity: .15; flex-shrink: 0;
  line-height: 1; letter-spacing: -2px;
}
.level-header-content {}
.level-tag {
  font-size: 11.5px; font-weight: 700; letter-spacing: .8px;
  text-transform: uppercase; margin-bottom: 4px; opacity: .7;
}
.level-header h2 { font-size: 22px; font-weight: 800; letter-spacing: -0.3px; margin-bottom: 6px; }
.level-header p { font-size: 14px; color: var(--text2); line-height: 1.6; }

/* ── Module Cards ── */
.module-list { display: flex; flex-direction: column; gap: 2px; }
.chapter-title {
  font-size: 12px; font-weight: 700; color: var(--text3);
  text-transform: uppercase; letter-spacing: .8px;
  padding: 16px 0 8px;
}
.module {
  border-radius: var(--r); overflow: hidden;
  border: 1px solid transparent; scroll-margin-top: calc(var(--nav-h) + 16px);
  transition: border-color var(--tr), background var(--tr);
  margin-bottom: 5px;
}
.module:hover { border-color: var(--border); background: var(--surface); }
.module-toggle { cursor: pointer; padding: 16px 20px; }
.module-title {
  font-size: 16px; font-weight: 700; color: var(--text);
  line-height: 1.45; margin-bottom: 4px;
}
.module-toggle:hover .module-title { color: var(--accent); }
.module-desc { font-size: 13.5px; color: var(--text2); line-height: 1.6; }
.read-more {
  display: flex; align-items: center; gap: 6px;
  font-size: 12.5px; color: var(--text3); margin-top: 10px;
  padding-top: 10px; border-top: 1px solid var(--border);
}
.read-more-line { flex: 1; height: 1px; background: var(--border); }
.module-toggle.open .read-more { display: none; }

.article-body {
  display: none; padding: 0 20px 24px; border-top: 1px solid var(--border);
}
.article-body.active { display: block; }
.article-body p {
  font-size: 15.5px; line-height: 2.0; color: rgba(26,25,22,.82);
  margin-bottom: 18px; text-align: justify; text-indent: 2em;
}
html[data-theme='dark'] .article-body p { color: rgba(240,238,230,.8); }
.article-body strong { color: var(--text); font-weight: 600; }
.article-body h3 {
  font-size: 16.5px; font-weight: 700; color: var(--text);
  margin: 32px 0 12px; padding-left: 12px;
  border-left: 3px solid var(--accent); line-height: 1.4;
}
.article-body h3:first-child { margin-top: 16px; }
.article-body ul, .article-body ol { padding-left: 24px; margin-bottom: 18px; }
.article-body li { font-size: 15px; line-height: 1.9; color: var(--text2); margin-bottom: 6px; }
.article-body table {
  width: 100%; border-collapse: collapse; margin: 20px 0;
  font-size: 13.5px; border-radius: 8px; overflow: hidden;
}
.article-body th {
  background: var(--surface2); padding: 11px 14px;
  text-align: left; color: var(--text); font-weight: 600;
  border-bottom: 1px solid var(--border);
}
.article-body td {
  padding: 10px 14px; color: var(--text2);
  border-bottom: 1px solid var(--border);
}
.article-body tr:last-child td { border-bottom: none; }
.article-body blockquote {
  border-radius: 10px; padding: 16px 20px; margin: 28px 0 8px;
  background: var(--surface2); border-left: 4px solid var(--accent);
}
.article-body blockquote p {
  margin-bottom: 0; font-size: 14px; line-height: 1.8;
  text-indent: 0 !important;
}

/* Locked module */
.module.locked {
  background: var(--surface2); border: 1px solid var(--border);
  padding: 16px 20px; border-radius: var(--r);
  display: flex; align-items: flex-start; gap: 14px;
}
.lock-icon { font-size: 18px; flex-shrink: 0; opacity: .4; margin-top: 2px; }
.lock-body {}
.lock-title { font-size: 15px; font-weight: 600; color: var(--text2); margin-bottom: 4px; }
.lock-desc { font-size: 13px; color: var(--text3); line-height: 1.55; }
.lock-badge {
  display: inline-flex; align-items: center; gap: 4px;
  font-size: 11.5px; font-weight: 600; color: var(--gold);
  background: var(--gold-lt); padding: 3px 8px; border-radius: 12px;
  margin-top: 8px;
}

/* Article end CTA */
.article-cta {
  margin: 48px 0; padding: 28px 32px;
  background: linear-gradient(135deg, var(--accent-lt), var(--teal-lt));
  border-radius: var(--r-lg); border: 1px solid rgba(201,150,58,.15);
  text-align: center;
}
.article-cta h3 { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.article-cta p { font-size: 14px; color: var(--text2); margin-bottom: 20px; line-height: 1.7; }

.enroll-banner {
  background: var(--accent); border-radius: var(--r-lg);
  padding: 32px; text-align: center; color: #fff; margin-top: 40px;
}
.enroll-banner h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.enroll-banner p { opacity: .85; margin-bottom: 20px; font-size: 14.5px; }

/* ── Research Layout ── */
.research-layout {
  display: grid; grid-template-columns: 260px 1fr;
  max-width: var(--max-w); margin: 0 auto; padding: 0 24px;
  gap: 0; min-height: calc(100vh - var(--nav-h));
}
.research-sidebar {
  position: sticky; top: var(--nav-h);
  height: calc(100vh - var(--nav-h)); overflow-y: auto;
  padding: 28px 0 40px; border-right: 1px solid var(--border);
  scrollbar-width: thin; scrollbar-color: var(--border) transparent;
}
.research-sidebar::-webkit-scrollbar { width: 4px; }
.research-sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
.research-sidebar-inner { padding: 0 16px 0 0; }
.research-category-title {
  font-size: 11px; font-weight: 700; letter-spacing: 1px;
  text-transform: uppercase; color: var(--text3);
  padding: 12px 12px 4px;
}
.research-content { padding: 40px 40px 80px; min-width: 0; }
.research-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: 28px 32px; margin-bottom: 20px;
  scroll-margin-top: calc(var(--nav-h) + 16px);
  transition: border-color var(--tr), box-shadow var(--tr);
}
.research-card:hover { border-color: var(--border2); box-shadow: var(--shadow); }
.research-card-tag {
  font-size: 11px; font-weight: 700; text-transform: uppercase;
  letter-spacing: .8px; color: var(--accent); margin-bottom: 10px;
}
.research-card h2 {
  font-size: 20px; font-weight: 800; margin-bottom: 12px; letter-spacing: -0.2px;
}
.research-card h3 {
  font-size: 16px; font-weight: 700; color: var(--text);
  margin: 20px 0 8px; border-left: 3px solid var(--accent);
  padding-left: 10px;
}
.research-card p { font-size: 14.5px; color: var(--text2); line-height: 1.75; margin-bottom: 12px; }
.research-card .pill-row { display: flex; gap: 6px; flex-wrap: wrap; margin: 14px 0; }
.pill {
  font-size: 12px; padding: 4px 10px; border-radius: 20px;
  background: var(--surface2); color: var(--text2); border: 1px solid var(--border);
}
.research-cta {
  margin-top: 20px; padding: 16px 20px;
  background: var(--gold-lt); border-radius: var(--r);
  border: 1px solid rgba(201,150,58,.2);
  display: flex; align-items: center; gap: 12px;
}
.research-cta-icon { font-size: 20px; flex-shrink: 0; }
.research-cta p { margin: 0; font-size: 13.5px; color: var(--text2); }
.research-cta strong { color: var(--text); }

/* ── Tools Grid ── */
.tools-section { padding: 48px 0 80px; }
.tools-category { margin-bottom: 40px; }
.tools-category-title {
  font-size: 16px; font-weight: 800; color: var(--text);
  letter-spacing: .3px;
  margin-bottom: 16px; display: flex; align-items: center; gap: 10px;
}
.tools-category-title::after { content: ''; flex: 1; height: 1px; background: var(--border); }
.tools-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.tool-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r); padding: 18px 20px;
  display: flex; align-items: flex-start; gap: 14px;
  transition: border-color var(--tr), box-shadow var(--tr), transform var(--tr);
  text-decoration: none;
}
.tool-card:hover { border-color: var(--accent); box-shadow: var(--shadow); transform: translateY(-2px); }
.tool-icon {
  width: 38px; height: 38px; border-radius: 10px;
  background: var(--surface2); display: flex; align-items: center;
  justify-content: center; font-size: 18px; flex-shrink: 0;
}
.tool-name { font-size: 14.5px; font-weight: 700; color: var(--text); margin-bottom: 3px; }
.tool-desc { font-size: 12.5px; color: var(--text2); line-height: 1.5; }
.tool-tag {
  display: inline-block; margin-top: 6px; font-size: 11px;
  padding: 2px 7px; border-radius: 10px;
  background: var(--accent-lt); color: var(--accent);
}

/* ── Topics ── */
.topics-layout { padding: 48px 0 80px; max-width: var(--max-w); margin: 0 auto; padding-left: 24px; padding-right: 24px; }
.topic-series { margin-bottom: 56px; }
.topic-series-header {
  display: flex; align-items: flex-start; gap: 16px;
  padding: 24px 28px; border-radius: var(--r-lg);
  border: 1px solid var(--border); background: var(--surface);
  margin-bottom: 16px;
}
.topic-series-icon {
  width: 48px; height: 48px; border-radius: 12px;
  background: var(--accent-lt); display: flex; align-items: center;
  justify-content: center; font-size: 22px; flex-shrink: 0;
}
.topic-series-name { font-size: 18px; font-weight: 800; margin-bottom: 6px; }
.topic-series-desc { font-size: 14px; color: var(--text2); line-height: 1.6; }
.topic-article {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r); padding: 20px 24px; margin-top: 10px;
  display: flex; align-items: center; gap: 14px;
}
.topic-article-dot { width: 10px; height: 10px; border-radius: 50%; background: var(--border); flex-shrink: 0; }
.topic-article-info { flex: 1; }
.topic-article-title { font-size: 15px; font-weight: 600; color: var(--text2); margin-bottom: 3px; }
.topic-article-meta { font-size: 12.5px; color: var(--text3); }

/* ── About ── */
.about-layout { max-width: 720px; margin: 0 auto; padding: 56px 24px 80px; }
.about-section { margin-bottom: 56px; }
.about-section h2 { font-size: 24px; font-weight: 800; margin-bottom: 20px; letter-spacing: -0.3px; }
.about-section p { font-size: 15.5px; color: var(--text2); line-height: 1.9; margin-bottom: 14px; }
.about-section strong { color: var(--text); }
.join-card {
  background: var(--accent); border-radius: var(--r-lg);
  padding: 36px 40px; color: #fff; text-align: center;
}
.join-card h2 { font-size: 26px; font-weight: 800; margin-bottom: 12px; }
.join-card p { opacity: .88; font-size: 15px; line-height: 1.75; margin-bottom: 24px; }
.join-card .includes {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 10px; margin-bottom: 28px; text-align: left;
}
.include-item {
  display: flex; align-items: flex-start; gap: 8px;
  font-size: 14px; opacity: .9;
}
.include-check { flex-shrink: 0; margin-top: 2px; }
.join-price { font-size: 13px; opacity: .7; margin-top: 14px; }

/* ── Footer ── */
.footer {
  background: var(--surface); border-top: 1px solid var(--border);
  padding: 48px 0 32px;
}
.footer-grid {
  display: grid; grid-template-columns: 1.4fr 1fr 1fr;
  gap: 40px; margin-bottom: 40px;
}
.footer-brand .footer-logo {
  font-size: 17px; font-weight: 800;
  display: flex; align-items: center; gap: 6px; margin-bottom: 12px;
}
.footer-brand p { font-size: 13.5px; color: var(--text2); line-height: 1.7; max-width: 280px; }
.footer-col-title {
  font-size: 12px; font-weight: 700; color: var(--text3);
  text-transform: uppercase; letter-spacing: .8px; margin-bottom: 14px;
}
.footer-col a {
  display: block; font-size: 14px; color: var(--text2);
  padding: 4px 0; transition: color var(--tr);
}
.footer-col a:hover { color: var(--text); }
.footer-bottom {
  padding-top: 24px; border-top: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  font-size: 13px; color: var(--text3);
}

/* ── Animations ── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}
.fade-up { animation: fadeUp .5s ease both; }
.fade-up-1 { animation-delay: .1s; }
.fade-up-2 { animation-delay: .2s; }
.fade-up-3 { animation-delay: .3s; }
.fade-up-4 { animation-delay: .4s; }

/* ── Responsive ── */
@media (max-width: 1024px) {
  .level-grid { grid-template-columns: repeat(2, 1fr); }
  .tools-grid { grid-template-columns: repeat(2, 1fr); }
  .course-layout, .research-layout { grid-template-columns: 220px 1fr; }
  .course-content, .research-content { padding: 32px 28px 60px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .nav-links, .nav-right .btn { display: none; }
  .nav-toggle { display: flex; }
  .theme-toggle { display: flex; }
  .course-layout, .research-layout { grid-template-columns: 1fr; }
  .sidebar, .research-sidebar { display: none; }
  .course-content, .research-content { padding: 24px 0 60px; }
  .level-grid { grid-template-columns: 1fr; }
  .tools-grid { grid-template-columns: 1fr; }
  .stats-inner { flex-wrap: wrap; }
  .stat-item { flex-basis: 50%; border-right: none; border-bottom: 1px solid var(--border); }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .hero { padding: 64px 0 56px; }
  .join-card .includes { grid-template-columns: 1fr; }
  .community-cta { padding: 32px 24px; }
  .hero-actions { flex-direction: column; align-items: center; }
}
/* 英雄区背景基础 */
.hero {
  position: relative;
  overflow: hidden;
  text-align: center;
  /* 居中对齐 */
  padding: 100px 0;
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
}

/* 网格线 */
.grid-lines {
  position: absolute;
  inset: 0;
  background-image: linear-gradient(to right, rgba(0, 0, 0, 0.05) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0, 0, 0, 0.05) 1px, transparent 1px);
  background-size: 40px 40px;
}

/* 渐变光球 */
.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.4;
}

.orb-1 {
  width: 400px;
  height: 400px;
  background: var(--color-primary);
  top: -100px;
  right: -100px;
}

.orb-2 {
  width: 300px;
  height: 300px;
  background: var(--color-secondary);
  bottom: -50px;
  left: -50px;
}