/* ============================================================
   星火智学 · SparkLearn — 设计系统
   ============================================================ */

:root {
  --bg: #0a0c11;
  --bg-soft: #0f1219;
  --surface: #141826;
  --surface-2: #1a1f30;
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.14);

  --text: #e9ecf4;
  --text-2: #a8afc1;
  --text-3: #6d7488;

  --brand-1: #6d7bff;
  --brand-2: #38d6f5;
  --brand-3: #b48cff;
  --brand-pink: #ff7ac6;
  --grad: linear-gradient(120deg, var(--brand-1) 0%, var(--brand-2) 100%);
  --grad-soft: linear-gradient(120deg, rgba(109, 123, 255, 0.18), rgba(56, 214, 245, 0.18));

  --success: #34d399;
  --warn: #fbbf24;
  --danger: #f87171;

  --font-sans: "Inter", "SF Pro Display", -apple-system, BlinkMacSystemFont,
    "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Noto Sans SC", sans-serif;
  --font-serif: "Playfair Display", "Noto Serif SC", "Songti SC", "STSong",
    "SimSun", serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Cascadia Code", Consolas,
    "Courier New", monospace;

  --radius: 18px;
  --radius-sm: 12px;
  --shadow-lg: 0 24px 60px -12px rgba(0, 0, 0, 0.55);
  --shadow-glow: 0 0 0 1px rgba(109, 123, 255, 0.25),
    0 12px 40px -8px rgba(109, 123, 255, 0.35);

  --nav-h: 72px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  font-size: 16px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: rgba(109, 123, 255, 0.4);
  color: #fff;
}

img,
svg {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

ul,
ol {
  list-style: none;
}

:focus-visible {
  outline: 2px solid var(--brand-2);
  outline-offset: 3px;
  border-radius: 4px;
}

::-webkit-scrollbar {
  width: 10px;
}
::-webkit-scrollbar-track {
  background: var(--bg);
}
::-webkit-scrollbar-thumb {
  background: #262c3d;
  border-radius: 8px;
  border: 2px solid var(--bg);
}
::-webkit-scrollbar-thumb:hover {
  background: #343c52;
}

/* ---------- 背景氛围 ---------- */
.bg-grid {
  background-image: linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: radial-gradient(ellipse 90% 70% at 50% 0%, #000 30%, transparent 72%);
  mask-image: radial-gradient(ellipse 90% 70% at 50% 0%, #000 30%, transparent 72%);
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.5;
  pointer-events: none;
  z-index: 0;
}

/* ---------- 通用 ---------- */
.container {
  width: min(1180px, 92%);
  margin-inline: auto;
  position: relative;
  z-index: 1;
}

section {
  position: relative;
  padding: 104px 0;
}

.section-head {
  max-width: 720px;
  margin-bottom: 56px;
}

.section-head.center {
  margin-inline: auto;
  text-align: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--brand-2);
  margin-bottom: 16px;
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--grad);
}

.section-head.center .eyebrow::after {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--grad);
}

h1,
h2,
h3 {
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

h2 {
  font-size: clamp(1.8rem, 3.6vw, 2.6rem);
  margin-bottom: 16px;
}

.section-head p {
  color: var(--text-2);
  font-size: 1.05rem;
}

.grad-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.serif {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 500;
  letter-spacing: 0;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  line-height: 1;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease,
    border-color 0.25s ease, color 0.25s ease;
  white-space: nowrap;
}

.btn svg {
  width: 17px;
  height: 17px;
  transition: transform 0.25s ease;
}

.btn:hover svg {
  transform: translateX(3px);
}

.btn-primary {
  background: var(--grad);
  color: #fff;
  box-shadow: 0 10px 30px -8px rgba(109, 123, 255, 0.6);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 40px -8px rgba(109, 123, 255, 0.7);
}

.btn-ghost {
  border: 1px solid var(--border-strong);
  color: var(--text);
  background: rgba(255, 255, 255, 0.02);
}

.btn-ghost:hover {
  transform: translateY(-2px);
  border-color: rgba(109, 123, 255, 0.6);
  background: rgba(109, 123, 255, 0.1);
  box-shadow: var(--shadow-glow);
}

.btn-lg {
  padding: 16px 34px;
  font-size: 16px;
}

.btn-block {
  width: 100%;
}

/* ---------- 导航 ---------- */
.site-nav {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--nav-h);
  z-index: 100;
  display: flex;
  align-items: center;
  transition: background 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
  border-bottom: 1px solid transparent;
}

.site-nav.scrolled {
  background: rgba(10, 12, 17, 0.78);
  -webkit-backdrop-filter: blur(18px);
  backdrop-filter: blur(18px);
  border-bottom-color: var(--border);
  box-shadow: 0 10px 40px -18px rgba(0, 0, 0, 0.7);
}

.nav-inner {
  width: min(1180px, 92%);
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 19px;
  letter-spacing: -0.01em;
}

.logo-mark {
  width: 38px;
  height: 38px;
  border-radius: 12px;
  background: var(--grad);
  display: grid;
  place-items: center;
  box-shadow: 0 8px 24px -6px rgba(109, 123, 255, 0.7);
}

.logo-mark svg {
  width: 20px;
  height: 20px;
  color: #fff;
}

.logo small {
  display: block;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--text-3);
  line-height: 1.2;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-links a {
  padding: 9px 16px;
  border-radius: 999px;
  font-size: 15px;
  color: var(--text-2);
  font-weight: 500;
  transition: color 0.2s ease, background 0.2s ease;
}

.nav-links a:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.05);
}

.nav-links a[aria-current="page"] {
  color: #fff;
  background: var(--grad-soft);
  box-shadow: inset 0 0 0 1px rgba(109, 123, 255, 0.35);
}

.nav-cta {
  display: flex;
  align-items: center;
  gap: 14px;
}

.nav-cta .btn {
  padding: 10px 20px;
  font-size: 14px;
}

.hamburger {
  display: none;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  border: 1px solid var(--border);
  place-items: center;
}

.hamburger span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
  position: relative;
}

.hamburger span::before,
.hamburger span::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s ease;
}

.hamburger span::before {
  top: -6px;
}
.hamburger span::after {
  top: 6px;
}

.hamburger.open span {
  background: transparent;
}
.hamburger.open span::before {
  transform: translateY(6px) rotate(45deg);
}
.hamburger.open span::after {
  transform: translateY(-6px) rotate(-45deg);
}

.mobile-menu {
  position: fixed;
  top: var(--nav-h);
  left: 0;
  right: 0;
  z-index: 99;
  background: rgba(10, 12, 17, 0.96);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 20px 6vw 28px;
  display: none;
  flex-direction: column;
  gap: 4px;
  transform: translateY(-12px);
  opacity: 0;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.mobile-menu.open {
  display: flex;
  transform: translateY(0);
  opacity: 1;
}

.mobile-menu a {
  padding: 13px 14px;
  font-size: 17px;
  font-weight: 600;
  color: var(--text-2);
  border-radius: 12px;
}

.mobile-menu a[aria-current="page"],
.mobile-menu a:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.06);
}

.mobile-menu .btn {
  margin-top: 14px;
}

/* ---------- Hero ---------- */
.hero {
  padding: calc(var(--nav-h) + 76px) 0 96px;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 64px;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 18px;
  border-radius: 999px;
  border: 1px solid rgba(109, 123, 255, 0.35);
  background: rgba(109, 123, 255, 0.08);
  font-size: 13.5px;
  font-weight: 600;
  color: #b9c2ff;
  margin-bottom: 26px;
}

.hero-badge .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 0 4px rgba(52, 211, 153, 0.18);
  animation: pulse 2.2s ease-in-out infinite;
}

@keyframes pulse {
  0%,
  100% {
    box-shadow: 0 0 0 3px rgba(52, 211, 153, 0.2);
  }
  50% {
    box-shadow: 0 0 0 7px rgba(52, 211, 153, 0.05);
  }
}

.hero h1 {
  font-size: clamp(2.5rem, 5.6vw, 4.1rem);
  margin-bottom: 24px;
}

.hero-sub {
  color: var(--text-2);
  font-size: 1.12rem;
  max-width: 540px;
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-meta {
  display: flex;
  gap: 36px;
  flex-wrap: wrap;
}

.hero-meta .m-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.hero-meta .m-num {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.hero-meta .m-label {
  font-size: 13px;
  color: var(--text-3);
}

/* Hero 视觉 */
.hero-visual {
  position: relative;
  min-height: 480px;
}

.mock-stage {
  position: relative;
  height: 480px;
}

.mock-card {
  position: absolute;
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0.02));
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  padding: 22px;
  animation: float 7s ease-in-out infinite;
}

.mock-card.main {
  width: min(400px, 88%);
  left: 0;
  top: 40px;
  z-index: 2;
  animation-delay: 0.4s;
}

.mock-card.mini-a {
  width: 250px;
  right: -8px;
  top: 0;
  z-index: 1;
  animation-delay: 1.2s;
}

.mock-card.mini-b {
  width: 260px;
  right: 18px;
  bottom: 8px;
  z-index: 3;
  animation-delay: 2s;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-12px);
  }
}

.mock-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.mock-title {
  font-weight: 700;
  font-size: 15px;
}

.mock-tag {
  font-size: 11px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  letter-spacing: 0.06em;
}

.mock-progress {
  height: 8px;
  border-radius: 99px;
  background: rgba(255, 255, 255, 0.08);
  overflow: hidden;
  margin: 14px 0 8px;
}

.mock-progress i {
  display: block;
  height: 100%;
  border-radius: 99px;
  background: var(--grad);
}

.mock-foot {
  display: flex;
  justify-content: space-between;
  font-size: 12.5px;
  color: var(--text-3);
}

.mock-lesson {
  display: flex;
  gap: 10px;
  align-items: center;
  padding: 9px 0;
  font-size: 13px;
  color: var(--text-2);
  border-top: 1px dashed rgba(255, 255, 255, 0.08);
}

.mock-lesson .ic {
  width: 26px;
  height: 26px;
  flex: none;
  border-radius: 8px;
  display: grid;
  place-items: center;
  font-size: 12px;
  background: rgba(109, 123, 255, 0.16);
  color: #aab4ff;
}

.mock-lesson.done .ic {
  background: rgba(52, 211, 153, 0.16);
  color: var(--success);
}

.mock-lesson.current {
  color: var(--text);
  font-weight: 600;
}

.mock-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 999px;
  background: rgba(20, 24, 38, 0.9);
  border: 1px solid var(--border-strong);
  margin-bottom: 10px;
}

.mock-chip svg {
  width: 14px;
  height: 14px;
}

/* ---------- 统计条 ---------- */
.stat-strip {
  border-block: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.015);
  padding: 44px 0;
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.stat {
  text-align: center;
}

.stat .num {
  font-size: clamp(1.9rem, 3.4vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.stat .num em {
  font-style: normal;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.stat .label {
  font-size: 13.5px;
  color: var(--text-3);
  margin-top: 4px;
}

/* ---------- 特性卡片 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.feature-card {
  padding: 30px 26px;
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.045), rgba(255, 255, 255, 0.015));
  border: 1px solid var(--border);
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: rgba(109, 123, 255, 0.45);
  box-shadow: 0 20px 50px -20px rgba(109, 123, 255, 0.35);
}

.feature-ic {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  margin-bottom: 20px;
  background: var(--grad-soft);
  border: 1px solid rgba(109, 123, 255, 0.3);
}

.feature-ic svg {
  width: 24px;
  height: 24px;
  color: var(--brand-2);
}

.feature-card h3 {
  font-size: 17.5px;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 14.5px;
  color: var(--text-2);
}

/* ---------- 学习路径卡片 ---------- */
.path-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.path-card {
  position: relative;
  padding: 34px 30px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.04), rgba(255, 255, 255, 0.012));
  overflow: hidden;
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.path-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: var(--grad);
  opacity: 0.85;
}

.path-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow-lg);
}

.path-num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-3);
  letter-spacing: 0.14em;
  margin-bottom: 14px;
}

.path-card h3 {
  font-size: 21px;
  margin-bottom: 10px;
}

.path-card > p {
  color: var(--text-2);
  font-size: 14.5px;
  margin-bottom: 22px;
}

.path-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.path-tags span {
  font-size: 12px;
  font-weight: 600;
  padding: 5px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border);
  color: var(--text-2);
}

.path-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 18px;
  border-top: 1px solid var(--border);
  font-size: 13.5px;
  color: var(--text-2);
}

.path-meta .link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--brand-2);
  font-weight: 600;
}

.path-meta .link svg {
  width: 15px;
  height: 15px;
  transition: transform 0.25s ease;
}

.path-card:hover .link svg {
  transform: translateX(4px);
}

/* ---------- 课程卡片 ---------- */
.course-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.course-card {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.course-card:hover {
  transform: translateY(-6px);
  border-color: rgba(109, 123, 255, 0.4);
  box-shadow: var(--shadow-lg);
}

.course-cover {
  height: 148px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.course-cover::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 70% 20%, rgba(255, 255, 255, 0.22), transparent 55%);
}

.course-cover svg {
  width: 46px;
  height: 46px;
  color: rgba(255, 255, 255, 0.95);
  filter: drop-shadow(0 6px 18px rgba(0, 0, 0, 0.35));
  position: relative;
  z-index: 1;
}

.course-cover .cover-tag {
  position: absolute;
  top: 14px;
  right: 14px;
  z-index: 2;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 5px 12px;
  border-radius: 999px;
  background: rgba(10, 12, 17, 0.55);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
  border: 1px solid rgba(255, 255, 255, 0.18);
  color: #fff;
}

.tint-1 { background: linear-gradient(125deg, #4f46e5, #7c3aed); }
.tint-2 { background: linear-gradient(125deg, #0ea5e9, #22d3ee); }
.tint-3 { background: linear-gradient(125deg, #059669, #34d399); }
.tint-4 { background: linear-gradient(125deg, #e11d48, #fb7185); }
.tint-5 { background: linear-gradient(125deg, #d97706, #fbbf24); }
.tint-6 { background: linear-gradient(125deg, #7c3aed, #c026d3); }

.course-body {
  padding: 22px 24px 24px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.course-tags {
  display: flex;
  gap: 8px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}

.course-tags span {
  font-size: 11.5px;
  font-weight: 600;
  padding: 4px 11px;
  border-radius: 999px;
  color: var(--text-2);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border);
}

.course-body h3 {
  font-size: 18px;
  margin-bottom: 10px;
  line-height: 1.45;
}

.course-body p {
  font-size: 14px;
  color: var(--text-2);
  margin-bottom: 20px;
  flex: 1;
}

.course-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-3);
}

.course-foot .meta {
  display: flex;
  gap: 14px;
  align-items: center;
}

.course-foot .meta span {
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.course-foot svg {
  width: 14px;
  height: 14px;
}

.course-foot .rating {
  color: var(--warn);
  font-weight: 700;
}

.rating svg {
  fill: var(--warn);
  color: var(--warn);
}

/* ---------- 文章卡片 ---------- */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.article-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.article-card:hover {
  transform: translateY(-6px);
  border-color: rgba(56, 214, 245, 0.4);
  box-shadow: var(--shadow-lg);
}

.article-cover {
  height: 170px;
  position: relative;
  overflow: hidden;
  display: grid;
  place-items: center;
}

.article-cover .a-word {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 56px;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.9);
  text-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

.article-cover::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(255, 255, 255, 0.25) 1px, transparent 1px);
  background-size: 22px 22px;
  opacity: 0.35;
}

.article-body {
  padding: 22px 24px 24px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.article-meta {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.article-meta span {
  font-size: 11.5px;
  font-weight: 600;
  padding: 4px 11px;
  border-radius: 999px;
  background: rgba(56, 214, 245, 0.09);
  border: 1px solid rgba(56, 214, 245, 0.25);
  color: #7fe3f7;
}

.article-meta span.gray {
  background: rgba(255, 255, 255, 0.04);
  border-color: var(--border);
  color: var(--text-3);
}

.article-body h3 {
  font-size: 17px;
  line-height: 1.5;
  margin-bottom: 10px;
}

.article-body p {
  font-size: 14px;
  color: var(--text-2);
  margin-bottom: 18px;
  flex: 1;
}

.article-foot {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 14px;
  border-top: 1px solid var(--border);
  font-size: 12.5px;
  color: var(--text-3);
}

.article-foot .link {
  color: var(--brand-2);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.article-foot .link svg {
  width: 14px;
  height: 14px;
}

/* ---------- 评价 ---------- */
.testi-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.testi-card {
  padding: 30px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.04), rgba(255, 255, 255, 0.01));
  display: flex;
  flex-direction: column;
  gap: 18px;
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.testi-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-strong);
}

.testi-stars {
  display: flex;
  gap: 4px;
  color: var(--warn);
}

.testi-stars svg {
  width: 16px;
  height: 16px;
  fill: var(--warn);
}

.testi-quote {
  font-size: 14.5px;
  color: var(--text-2);
  flex: 1;
}

.testi-quote .serif {
  color: var(--text);
  font-size: 15.5px;
}

.testi-user {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}

.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 15px;
  color: #fff;
  flex: none;
}

.avatar.a1 { background: linear-gradient(135deg, #6d7bff, #38d6f5); }
.avatar.a2 { background: linear-gradient(135deg, #e11d48, #fb7185); }
.avatar.a3 { background: linear-gradient(135deg, #059669, #34d399); }
.avatar.a4 { background: linear-gradient(135deg, #d97706, #fbbf24); }
.avatar.a5 { background: linear-gradient(135deg, #7c3aed, #c026d3); }
.avatar.a6 { background: linear-gradient(135deg, #0284c7, #22d3ee); }
.avatar.lg {
  width: 72px;
  height: 72px;
  font-size: 24px;
}

.testi-user .name {
  font-weight: 700;
  font-size: 14.5px;
}

.testi-user .role {
  font-size: 12.5px;
  color: var(--text-3);
}

/* ---------- CTA 横幅 ---------- */
.cta-banner {
  border-radius: 26px;
  padding: 72px 56px;
  text-align: center;
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, rgba(109, 123, 255, 0.16), rgba(56, 214, 245, 0.1)),
    var(--surface);
  border: 1px solid rgba(109, 123, 255, 0.3);
}

.cta-banner::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(109, 123, 255, 0.18) 1px, transparent 1px);
  background-size: 26px 26px;
  mask-image: radial-gradient(ellipse 60% 90% at 50% 50%, #000, transparent);
  -webkit-mask-image: radial-gradient(ellipse 60% 90% at 50% 50%, #000, transparent);
}

.cta-banner h2 {
  margin-bottom: 14px;
  position: relative;
}

.cta-banner p {
  color: var(--text-2);
  max-width: 560px;
  margin: 0 auto 34px;
  position: relative;
}

.cta-banner .hero-actions {
  justify-content: center;
  margin-bottom: 0;
}

/* ---------- 页脚 ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-soft);
  padding: 72px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 56px;
}

.footer-brand p {
  color: var(--text-2);
  font-size: 14.5px;
  margin: 18px 0 22px;
  max-width: 320px;
}

.footer-social {
  display: flex;
  gap: 12px;
}

.footer-social a {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  border: 1px solid var(--border);
  display: grid;
  place-items: center;
  color: var(--text-2);
  transition: all 0.25s ease;
}

.footer-social a:hover {
  color: #fff;
  border-color: rgba(109, 123, 255, 0.6);
  background: rgba(109, 123, 255, 0.12);
  transform: translateY(-3px);
}

.footer-social svg {
  width: 18px;
  height: 18px;
}

.footer-col h4 {
  font-size: 14px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 20px;
  font-weight: 700;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col a {
  font-size: 14.5px;
  color: var(--text-2);
  transition: color 0.2s ease;
}

.footer-col a:hover {
  color: var(--brand-2);
}

.footer-bottom {
  border-top: 1px solid var(--border);
  padding: 24px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--text-3);
}

.footer-bottom a:hover {
  color: var(--text-2);
}

/* ---------- 内页 Hero ---------- */
.page-hero {
  padding: calc(var(--nav-h) + 88px) 0 72px;
  overflow: hidden;
}

.page-hero h1 {
  font-size: clamp(2.3rem, 5vw, 3.5rem);
  margin-bottom: 18px;
}

.page-hero .lead {
  color: var(--text-2);
  font-size: 1.1rem;
  max-width: 640px;
}

.crumbs {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  color: var(--text-3);
  margin-bottom: 26px;
}

.crumbs a:hover {
  color: var(--brand-2);
}

.crumbs svg {
  width: 13px;
  height: 13px;
}

/* ---------- 筛选器 ---------- */
.filter-bar {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.chip {
  padding: 9px 20px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-2);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
  transition: all 0.25s ease;
}

.chip:hover {
  color: var(--text);
  border-color: var(--border-strong);
}

.chip.active {
  color: #fff;
  background: var(--grad);
  border-color: transparent;
  box-shadow: 0 8px 24px -8px rgba(109, 123, 255, 0.6);
}

/* ---------- FAQ ---------- */
.faq-wrap {
  max-width: 780px;
  margin-inline: auto;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  margin-bottom: 14px;
  overflow: hidden;
  transition: border-color 0.25s ease;
}

.faq-item[open] {
  border-color: rgba(109, 123, 255, 0.4);
}

.faq-item summary {
  cursor: pointer;
  list-style: none;
  padding: 20px 24px;
  font-weight: 600;
  font-size: 15.5px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  font-size: 22px;
  color: var(--brand-2);
  transition: transform 0.3s ease;
  font-weight: 400;
  line-height: 1;
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item .faq-body {
  padding: 0 24px 22px;
  color: var(--text-2);
  font-size: 14.5px;
}

/* ---------- Tabs ---------- */
.tabs {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.tab-btn {
  padding: 10px 22px;
  border-radius: 999px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text-2);
  border: 1px solid var(--border);
  transition: all 0.25s ease;
}

.tab-btn:hover {
  color: var(--text);
  border-color: var(--border-strong);
}

.tab-btn.active {
  color: #fff;
  background: var(--grad);
  border-color: transparent;
  box-shadow: 0 8px 24px -8px rgba(109, 123, 255, 0.5);
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: grid;
  animation: fadeUp 0.5s ease both;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ---------- 资源卡片 ---------- */
.res-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.res-card {
  padding: 26px 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  display: flex;
  gap: 18px;
  align-items: flex-start;
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.res-card:hover {
  transform: translateY(-5px);
  border-color: rgba(56, 214, 245, 0.45);
  box-shadow: var(--shadow-lg);
}

.res-ic {
  width: 48px;
  height: 48px;
  flex: none;
  border-radius: 13px;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 17px;
  color: #fff;
}

.res-info {
  flex: 1;
}

.res-info h3 {
  font-size: 16px;
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.res-info h3 .ext {
  width: 14px;
  height: 14px;
  color: var(--text-3);
  flex: none;
}

.res-info p {
  font-size: 13.5px;
  color: var(--text-2);
  margin-bottom: 8px;
}

.res-info .res-tag {
  font-size: 11.5px;
  color: var(--brand-2);
  font-weight: 600;
  letter-spacing: 0.04em;
}

/* ---------- 时间线 ---------- */
.timeline {
  position: relative;
  max-width: 860px;
  margin-inline: auto;
  padding-left: 34px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--brand-1), var(--brand-2), transparent);
}

.tl-item {
  position: relative;
  padding-bottom: 44px;
}

.tl-item:last-child {
  padding-bottom: 0;
}

.tl-item::before {
  content: "";
  position: absolute;
  left: -32px;
  top: 7px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--bg);
  border: 3px solid var(--brand-1);
  box-shadow: 0 0 0 5px rgba(109, 123, 255, 0.15);
}

.tl-item:nth-child(2)::before {
  border-color: var(--brand-2);
  box-shadow: 0 0 0 5px rgba(56, 214, 245, 0.15);
}

.tl-item:nth-child(3)::before {
  border-color: var(--brand-3);
  box-shadow: 0 0 0 5px rgba(180, 140, 255, 0.15);
}

.tl-item:nth-child(4)::before {
  border-color: var(--brand-pink);
  box-shadow: 0 0 0 5px rgba(255, 122, 198, 0.15);
}

.tl-item:nth-child(5)::before {
  border-color: var(--success);
  box-shadow: 0 0 0 5px rgba(52, 211, 153, 0.15);
}

.tl-phase {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.16em;
  color: var(--brand-2);
  font-weight: 600;
  margin-bottom: 6px;
}

.tl-item h3 {
  font-size: 19px;
  margin-bottom: 6px;
}

.tl-item p {
  color: var(--text-2);
  font-size: 14.5px;
  max-width: 640px;
  margin-bottom: 10px;
}

.tl-meta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 12.5px;
  color: var(--text-3);
}

.tl-meta span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.tl-meta svg {
  width: 13px;
  height: 13px;
}

/* ---------- 团队 ---------- */
.team-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.team-card {
  text-align: center;
  padding: 34px 22px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.04), rgba(255, 255, 255, 0.01));
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.team-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-strong);
}

.team-card .avatar {
  margin: 0 auto 18px;
}

.team-card h3 {
  font-size: 17px;
  margin-bottom: 4px;
}

.team-card .role {
  font-size: 13px;
  color: var(--brand-2);
  font-weight: 600;
  margin-bottom: 12px;
}

.team-card p {
  font-size: 13.5px;
  color: var(--text-2);
}

/* ---------- 里程碑 ---------- */
.mile-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.mile-card {
  padding: 28px 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.mile-card:hover {
  transform: translateY(-5px);
  border-color: rgba(109, 123, 255, 0.4);
}

.mile-date {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--brand-2);
  font-weight: 700;
  margin-bottom: 10px;
}

.mile-card h3 {
  font-size: 15.5px;
  margin-bottom: 6px;
}

.mile-card p {
  font-size: 13.5px;
  color: var(--text-2);
}

/* ---------- 订阅 ---------- */
.newsletter {
  position: relative;
  overflow: hidden;
}

.news-form {
  display: flex;
  gap: 12px;
  max-width: 520px;
  margin-inline: auto;
  margin-top: 32px;
}

.news-form input {
  flex: 1;
  padding: 14px 22px;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  font: inherit;
  font-size: 15px;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
  min-width: 0;
}

.news-form input::placeholder {
  color: var(--text-3);
}

.news-form input:focus {
  outline: none;
  border-color: rgba(109, 123, 255, 0.6);
  box-shadow: 0 0 0 4px rgba(109, 123, 255, 0.15);
}

.news-note {
  margin-top: 14px;
  font-size: 12.5px;
  color: var(--text-3);
  text-align: center;
}

/* ---------- 滚动显现 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.in {
  opacity: 1;
  transform: none;
}

.reveal-d1 { transition-delay: 0.08s; }
.reveal-d2 { transition-delay: 0.16s; }
.reveal-d3 { transition-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html {
    scroll-behavior: auto;
  }
  .reveal {
    opacity: 1;
    transform: none;
  }
}

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 36px;
  transform: translateX(-50%) translateY(20px);
  background: var(--surface-2);
  border: 1px solid rgba(52, 211, 153, 0.5);
  color: var(--text);
  padding: 14px 24px;
  border-radius: 999px;
  font-size: 14.5px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.35s ease, transform 0.35s ease;
  z-index: 200;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.toast svg {
  width: 18px;
  height: 18px;
  color: var(--success);
}

/* 博客精选宽卡 */
.featured-wide {
  flex-direction: row;
}

.featured-wide .course-cover {
  flex: 0 0 46%;
}

@media (max-width: 768px) {
  .featured-wide {
    flex-direction: column !important;
  }
  .featured-wide .course-cover {
    min-height: 200px !important;
    flex: none !important;
  }
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 56px;
  }
  .hero-visual {
    max-width: 560px;
    margin-inline: auto;
    width: 100%;
  }
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .path-grid,
  .course-grid,
  .article-grid,
  .testi-grid,
  .res-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .team-grid,
  .mile-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: 1.4fr 1fr 1fr;
  }
  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  section {
    padding: 76px 0;
  }
  .nav-links,
  .nav-cta .btn {
    display: none;
  }
  .hamburger {
    display: grid;
  }
  .feature-grid,
  .path-grid,
  .course-grid,
  .article-grid,
  .testi-grid,
  .res-grid,
  .team-grid,
  .mile-grid {
    grid-template-columns: 1fr;
  }
  .stat-row {
    grid-template-columns: repeat(2, 1fr);
    gap: 32px 16px;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 36px;
  }
  .cta-banner {
    padding: 52px 28px;
  }
  .hero {
    padding-top: calc(var(--nav-h) + 48px);
  }
  .hero-actions .btn {
    flex: 1;
  }
  .news-form {
    flex-direction: column;
  }
  .news-form .btn {
    width: 100%;
  }
}

@media (max-width: 480px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .hero-meta {
    gap: 24px;
  }
  .mock-card {
    padding: 16px;
  }
  .mock-card.mini-a,
  .mock-card.mini-b {
    display: none;
  }
}