/* ================================================================
   赵汝飞练字 · 水墨国风 设计系统
   仅使用 5 种主色 + 字号/间距规范
   ================================================================ */
:root {
  /* —— 水墨五色 —— */
  --ink:        #1a1d1f;   /* 墨黑 */
  --ink-soft:   #2b2e30;   /* 浓墨 */
  --ink-light:  #6a655f;   /* 淡墨 */
  --paper:      #f3ecd9;   /* 宣纸 */
  --paper-deep: #e6dabd;   /* 深宣纸 */
  --cinnabar:   #a8322d;   /* 朱砂 */

  /* —— 派生 —— */
  --line:       rgba(26, 29, 31, 0.14);
  --line-soft:  rgba(26, 29, 31, 0.07);
  --shadow:     0 24px 60px -28px rgba(26, 29, 31, 0.4);
  --shadow-sm:  0 8px 24px -10px rgba(26, 29, 31, 0.25);

  /* —— 字体 —— */
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", serif;
  --font-brush: "Ma Shan Zheng", "ZCOOL XiaoWei", "Noto Serif SC", serif;
  --font-deco:  "ZCOOL XiaoWei", "Noto Serif SC", serif;
  --font-num:   "ZCOOL QingKe HuangYou", "Noto Serif SC", serif;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { margin: 0; padding: 0; }

html {
  font-size: 15px;
  scroll-behavior: smooth;
  background: var(--paper);
}

body {
  font-family: var(--font-serif);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.7;
  overflow-x: hidden;
  min-height: 100vh;
  position: relative;
}

/* —— 宣纸纹理（纯 CSS，不引入图片）—— */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  background-image:
    radial-gradient(rgba(106, 101, 95, 0.05) 1px, transparent 1px),
    radial-gradient(rgba(106, 101, 95, 0.04) 1px, transparent 1px);
  background-size: 3px 3px, 9px 9px;
  background-position: 0 0, 1px 2px;
  opacity: 0.7;
  mix-blend-mode: multiply;
}

body::after {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  background:
    radial-gradient(ellipse at top, transparent 50%, rgba(230, 218, 189, 0.5) 100%),
    radial-gradient(ellipse at bottom, transparent 60%, rgba(26, 29, 31, 0.08) 100%);
}

main, header, footer, section { position: relative; z-index: 2; }

/* —— 字号刻度 —— */
h1, h2, h3, h4 { margin: 0; font-weight: 400; letter-spacing: 0.04em; line-height: 1.25; }
h1 { font-family: var(--font-brush); font-size: 2.4rem; }
h2 { font-family: var(--font-deco); font-size: 1.7rem; }
h3 { font-family: var(--font-deco); font-size: 1.25rem; }
p  { margin: 0 0 0.8em 0; }

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

/* ================================================================
   顶栏
   ================================================================ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.7rem 1.2rem;
  background: rgba(243, 236, 217, 0.72);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--line-soft);
  transition: background 0.3s, padding 0.3s;
}
.nav.scrolled {
  padding: 0.45rem 1.2rem;
  background: rgba(243, 236, 217, 0.92);
  box-shadow: 0 4px 24px -16px rgba(26, 29, 31, 0.3);
}
.nav__brand {
  display: flex;
  align-items: center;
  gap: 0.55rem;
}
.nav__seal {
  width: 36px;
  height: 36px;
  background: var(--cinnabar);
  color: var(--paper);
  display: grid;
  place-items: center;
  font-family: var(--font-brush);
  font-size: 1.1rem;
  border-radius: 4px;
  position: relative;
  box-shadow: 0 2px 6px -2px rgba(168, 50, 45, 0.5);
}
.nav__seal::after {
  content: '';
  position: absolute;
  inset: 3px;
  border: 1px solid rgba(243, 236, 217, 0.55);
  border-radius: 2px;
}
.nav__title {
  display: flex;
  flex-direction: column;
  line-height: 1;
}
.nav__title-main {
  font-family: var(--font-brush);
  font-size: 1.1rem;
  letter-spacing: 0.12em;
}
.nav__title-sub {
  font-size: 0.62rem;
  color: var(--ink-light);
  letter-spacing: 0.32em;
  margin-top: 3px;
}
.nav__menu {
  display: flex;
  gap: 1.4rem;
  list-style: none;
  padding: 0;
  margin: 0;
}
.nav__menu a {
  font-size: 0.92rem;
  letter-spacing: 0.12em;
  position: relative;
  padding: 0.2rem 0;
  color: var(--ink-soft);
}
.nav__menu a::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: -2px;
  width: 0;
  height: 1.5px;
  background: var(--cinnabar);
  transition: width 0.3s, left 0.3s;
}
.nav__menu a:hover::after { width: 100%; left: 0; }
.nav__cta {
  font-size: 0.85rem;
  border: 1px solid var(--ink);
  padding: 0.4rem 0.95rem;
  letter-spacing: 0.18em;
  transition: all 0.3s;
}
.nav__cta:hover { background: var(--ink); color: var(--paper); }
.nav__burger {
  display: none;
  width: 30px;
  height: 22px;
  position: relative;
  cursor: pointer;
}
.nav__burger span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 1.4px;
  background: var(--ink);
  transition: all 0.3s;
}
.nav__burger span:nth-child(1) { top: 0; }
.nav__burger span:nth-child(2) { top: 50%; transform: translateY(-50%); }
.nav__burger span:nth-child(3) { bottom: 0; }
.nav__burger.open span:nth-child(1) { top: 50%; transform: rotate(45deg); }
.nav__burger.open span:nth-child(2) { opacity: 0; }
.nav__burger.open span:nth-child(3) { bottom: 50%; transform: rotate(-45deg) translateY(50%); }

/* ================================================================
   主视觉
   ================================================================ */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 7rem 1.2rem 4rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero__ink-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}
.hero__ink-bg svg {
  width: 100%;
  height: 100%;
  position: absolute;
  inset: 0;
}
.hero__pre {
  font-family: var(--font-deco);
  font-size: 0.85rem;
  letter-spacing: 0.6em;
  color: var(--ink-light);
  margin-bottom: 1.4rem;
  padding-left: 0.6em;
  opacity: 0;
  animation: fadeUp 1s 0.2s forwards;
}
.hero__title {
  font-family: var(--font-brush);
  font-size: clamp(2.4rem, 11vw, 5.8rem);
  font-weight: 400;
  letter-spacing: 0.06em;
  margin: 0;
  line-height: 1;
  position: relative;
}
.hero__title-row {
  display: flex;
  justify-content: center;
  align-items: baseline;
  gap: 0.08em;
  flex-wrap: nowrap;
  white-space: nowrap;
}
.hero__title-char {
  display: inline-block;
  opacity: 0;
  transform: translateY(40px) rotate(-6deg);
  animation: charDrop 0.9s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}
.hero__title-char:nth-child(1) { animation-delay: 0.30s; }
.hero__title-char:nth-child(2) { animation-delay: 0.45s; }
.hero__title-char:nth-child(3) { animation-delay: 0.60s; }
.hero__title-char:nth-child(4) { animation-delay: 0.75s; }
.hero__title-char:nth-child(5) { animation-delay: 0.90s; }
.hero__sub {
  font-family: var(--font-deco);
  font-size: clamp(1rem, 3.6vw, 1.35rem);
  letter-spacing: 0.5em;
  color: var(--ink-soft);
  margin-top: 1.8rem;
  padding-left: 0.5em;
  opacity: 0;
  animation: fadeUp 1s 1.6s forwards;
}
.hero__divider {
  width: 0;
  height: 1px;
  background: var(--ink-soft);
  margin: 1.6rem auto;
  animation: lineGrow 1.2s 1.8s forwards;
}
@keyframes lineGrow { to { width: clamp(140px, 30vw, 280px); } }

.hero__desc {
  max-width: 560px;
  font-size: 0.97rem;
  line-height: 2;
  color: var(--ink-soft);
  margin: 0 auto;
  opacity: 0;
  animation: fadeUp 1s 2s forwards;
}
.hero__cta {
  margin-top: 2.4rem;
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  opacity: 0;
  animation: fadeUp 1s 2.2s forwards;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.85rem 1.8rem;
  font-family: var(--font-deco);
  font-size: 0.95rem;
  letter-spacing: 0.3em;
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  transition: all 0.35s cubic-bezier(0.3, 0.7, 0.3, 1);
  position: relative;
  overflow: hidden;
  padding-left: 1.95rem;
}
.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 0;
  height: 100%;
  background: var(--ink);
  z-index: 0;
  transition: width 0.35s cubic-bezier(0.3, 0.7, 0.3, 1);
}
.btn > * { position: relative; z-index: 1; }
.btn:hover { color: var(--paper); }
.btn:hover::before { width: 100%; }
.btn--cinnabar { border-color: var(--cinnabar); color: var(--cinnabar); }
.btn--cinnabar::before { background: var(--cinnabar); }
.btn--cinnabar:hover { color: var(--paper); }
.btn--ghost { border-color: var(--ink-light); color: var(--ink-soft); }
.btn--small { padding: 0.55rem 1.1rem; font-size: 0.82rem; letter-spacing: 0.2em; }

/* Hero floating couplets */
.hero__couplet {
  position: absolute;
  font-family: var(--font-brush);
  font-size: clamp(1.3rem, 4vw, 1.8rem);
  letter-spacing: 0.15em;
  color: var(--ink-soft);
  writing-mode: vertical-rl;
  opacity: 0;
  animation: coupletAppear 1.6s 2.4s forwards;
}
.hero__couplet--left { left: 4%; top: 18%; }
.hero__couplet--right { right: 4%; top: 18%; }
@keyframes coupletAppear { from { opacity: 0; transform: translateY(-20px); } to { opacity: 0.4; transform: translateY(0); } }

.hero__scroll {
  position: absolute;
  bottom: 2.2rem;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.7rem;
  letter-spacing: 0.5em;
  color: var(--ink-light);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  opacity: 0;
  animation: fadeUp 1s 2.6s forwards;
}
.hero__scroll-line {
  width: 1px;
  height: 36px;
  background: linear-gradient(var(--ink-light) 50%, transparent 50%);
  background-size: 100% 8px;
  animation: scrollLine 1.8s linear infinite;
}
@keyframes scrollLine { from { background-position-y: 0; } to { background-position-y: 36px; } }

/* ================================================================
   通用 section 容器
   ================================================================ */
.section {
  padding: 6rem 1.2rem 5rem;
  max-width: 1180px;
  margin: 0 auto;
  position: relative;
}
.section__head {
  text-align: center;
  margin-bottom: 3.6rem;
  position: relative;
}
.section__num {
  font-family: var(--font-num);
  font-size: 5rem;
  color: var(--paper-deep);
  line-height: 0.9;
  letter-spacing: 0;
  user-select: none;
}
.section__title {
  font-family: var(--font-brush);
  font-size: 2.2rem;
  letter-spacing: 0.2em;
  margin-top: -2.6rem;
  position: relative;
  padding-left: 0.2em;
}
.section__sub {
  font-family: var(--font-deco);
  font-size: 0.82rem;
  letter-spacing: 0.5em;
  color: var(--ink-light);
  margin-top: 0.6rem;
  padding-left: 0.5em;
}
.section__title::after {
  content: '';
  display: block;
  width: 40px;
  height: 1.5px;
  background: var(--cinnabar);
  margin: 1rem auto 0;
}

/* ================================================================
   AI 教学六维卡片
   ================================================================ */
.teach {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.4rem;
}
.teach__card {
  background: rgba(243, 236, 217, 0.5);
  border: 1px solid var(--line);
  padding: 2rem 1.6rem;
  position: relative;
  transition: transform 0.4s cubic-bezier(0.3, 0.7, 0.3, 1), box-shadow 0.4s;
  overflow: hidden;
}
.teach__card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--cinnabar), transparent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.5s;
}
.teach__card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow);
}
.teach__card:hover::before { transform: scaleX(1); }
.teach__icon {
  width: 60px;
  height: 60px;
  display: grid;
  place-items: center;
  margin-bottom: 1.2rem;
  border: 1px solid var(--ink);
  border-radius: 50%;
  background: var(--paper);
  position: relative;
}
.teach__icon svg { width: 30px; height: 30px; stroke: var(--ink); fill: none; stroke-width: 1.5; }
.teach__title {
  font-family: var(--font-brush);
  font-size: 1.5rem;
  letter-spacing: 0.1em;
  margin-bottom: 0.8rem;
}
.teach__desc {
  font-size: 0.92rem;
  color: var(--ink-soft);
  line-height: 1.9;
  margin-bottom: 1.2rem;
}
.teach__points {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.teach__points li {
  font-size: 0.82rem;
  color: var(--ink-soft);
  padding-left: 1.4rem;
  position: relative;
  letter-spacing: 0.05em;
}
.teach__points li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 12px;
  height: 1px;
  background: var(--cinnabar);
}
.teach__corner {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  font-family: var(--font-num);
  font-size: 1.1rem;
  color: var(--paper-deep);
}

/* ================================================================
   AI 体验区（嵌入小型 demo）
   ================================================================ */
.experience {
  background: var(--ink);
  color: var(--paper);
  padding: 5rem 1.2rem;
  position: relative;
  overflow: hidden;
}
.experience::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 30%, rgba(168, 50, 45, 0.18), transparent 40%),
    radial-gradient(circle at 80% 70%, rgba(243, 236, 217, 0.07), transparent 50%);
  pointer-events: none;
}
.experience__inner {
  max-width: 1180px;
  margin: 0 auto;
  position: relative;
  display: grid;
  gap: 3rem;
  grid-template-columns: 1.05fr 1fr;
  align-items: center;
}
.experience .section__num { color: rgba(243, 236, 217, 0.08); }
.experience .section__title { color: var(--paper); }
.experience .section__title::after { background: var(--cinnabar); }
.experience .section__sub { color: rgba(243, 236, 217, 0.6); }
.experience__intro {
  font-size: 1rem;
  color: rgba(243, 236, 217, 0.78);
  line-height: 2;
  margin-bottom: 1.6rem;
}
.experience__features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-top: 1.5rem;
}
.experience__feature {
  border: 1px solid rgba(243, 236, 217, 0.15);
  padding: 0.85rem 1rem;
  display: flex;
  align-items: center;
  gap: 0.8rem;
}
.experience__feature-icon {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  font-family: var(--font-brush);
  font-size: 1.4rem;
  background: var(--cinnabar);
  color: var(--paper);
  flex-shrink: 0;
  border-radius: 2px;
}
.experience__feature-title {
  font-family: var(--font-brush);
  font-size: 1.05rem;
  letter-spacing: 0.1em;
  color: var(--paper);
}
.experience__feature-desc {
  font-size: 0.74rem;
  color: rgba(243, 236, 217, 0.6);
  margin-top: 0.2rem;
  letter-spacing: 0.04em;
}
.experience__canvas-wrap {
  background: var(--paper);
  color: var(--ink);
  padding: 1.6rem;
  position: relative;
  border-radius: 2px;
  box-shadow: 0 30px 80px -20px rgba(0, 0, 0, 0.55);
}
.canvas-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}
.canvas-head__hint {
  font-size: 0.75rem;
  letter-spacing: 0.3em;
  color: var(--ink-light);
}
.canvas-head__tabs {
  display: flex;
  gap: 0.6rem;
}
.canvas-head__tab {
  font-family: var(--font-brush);
  font-size: 1.2rem;
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  background: var(--paper);
  cursor: pointer;
  transition: all 0.25s;
}
.canvas-head__tab.is-active {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}
.canvas-board {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  background:
    linear-gradient(var(--line) 1px, transparent 1px) 50% 50% / 50% 50% no-repeat,
    linear-gradient(90deg, var(--line) 1px, transparent 1px) 50% 50% / 50% 50% no-repeat,
    repeating-linear-gradient(45deg, transparent 0, transparent 49.5%, var(--line-soft) 49.5%, var(--line-soft) 50.5%),
    var(--paper-deep);
  border: 1px solid var(--ink);
}
.canvas-board__guide {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: var(--font-brush);
  font-size: clamp(8rem, 28vw, 14rem);
  color: rgba(26, 29, 31, 0.07);
  pointer-events: none;
  user-select: none;
  transition: opacity 0.4s;
}
.canvas-board canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  touch-action: none;
  cursor: crosshair;
}
.canvas-tools {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 1rem;
  gap: 0.8rem;
  flex-wrap: wrap;
}
.canvas-tools__left {
  font-size: 0.78rem;
  color: var(--ink-light);
  letter-spacing: 0.16em;
}
.canvas-tools__right {
  display: flex;
  gap: 0.6rem;
}
.canvas-result {
  margin-top: 1rem;
  padding: 1.2rem;
  background: var(--paper-deep);
  border: 1px dashed var(--line);
  min-height: 80px;
  font-size: 0.9rem;
  display: none;
}
.canvas-result.is-show { display: block; animation: fadeUp 0.6s; }
.canvas-result__top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 0.6rem;
}
.canvas-result__score {
  font-family: var(--font-num);
  font-size: 2.6rem;
  color: var(--cinnabar);
  line-height: 1;
}
.canvas-result__grade {
  font-family: var(--font-brush);
  font-size: 1.2rem;
}
.canvas-result__bars {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin: 0.8rem 0;
}
.canvas-result__bar {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.8rem;
}
.canvas-result__bar-label { width: 4em; color: var(--ink-soft); letter-spacing: 0.1em; }
.canvas-result__bar-track {
  flex: 1;
  height: 6px;
  background: rgba(26, 29, 31, 0.1);
  position: relative;
  overflow: hidden;
}
.canvas-result__bar-fill {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, var(--ink), var(--cinnabar));
  width: 0;
  transition: width 1s cubic-bezier(0.3, 0.7, 0.3, 1);
}
.canvas-result__bar-num { width: 2em; font-family: var(--font-num); text-align: right; }
.canvas-result__metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1rem;
  font-size: 0.74rem;
  color: var(--ink-light);
  margin: 0.6rem 0 0.4rem;
  padding: 0.5rem 0;
  border-top: 1px dashed var(--line);
  border-bottom: 1px dashed var(--line);
  letter-spacing: 0.05em;
}
.canvas-result__feedback {
  font-size: 0.86rem;
  color: var(--ink-soft);
  line-height: 1.9;
  margin-top: 0.6rem;
}

/* ================================================================
   课程
   ================================================================ */
.courses {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.4rem;
}
.course-card {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 2rem 1.6rem 1.8rem;
  position: relative;
  overflow: hidden;
  transition: all 0.4s cubic-bezier(0.3, 0.7, 0.3, 1);
  cursor: pointer;
}
.course-card::after {
  content: '';
  position: absolute;
  top: 0; right: 0;
  width: 60px; height: 60px;
  background: linear-gradient(135deg, transparent 50%, var(--paper-deep) 50%);
}
.course-card:hover {
  transform: translateY(-4px);
  border-color: var(--ink);
  box-shadow: var(--shadow);
}
.course-card__level {
  display: inline-block;
  font-family: var(--font-deco);
  font-size: 0.7rem;
  letter-spacing: 0.32em;
  color: var(--cinnabar);
  border: 1px solid var(--cinnabar);
  padding: 0.15rem 0.6rem;
  margin-bottom: 1rem;
}
.course-card__name {
  font-family: var(--font-brush);
  font-size: 2rem;
  letter-spacing: 0.1em;
  margin-bottom: 0.4rem;
}
.course-card__tagline {
  font-size: 0.85rem;
  letter-spacing: 0.18em;
  color: var(--ink-light);
  margin-bottom: 1rem;
}
.course-card__desc {
  font-size: 0.86rem;
  color: var(--ink-soft);
  line-height: 1.9;
  margin-bottom: 1rem;
}
.course-card__tags {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 1.2rem;
}
.course-card__tag {
  font-size: 0.72rem;
  padding: 0.15rem 0.5rem;
  background: var(--paper-deep);
  color: var(--ink-soft);
  letter-spacing: 0.05em;
}
.course-card__foot {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  border-top: 1px dashed var(--line);
  padding-top: 1rem;
}
.course-card__more {
  font-family: var(--font-deco);
  font-size: 0.85rem;
  letter-spacing: 0.25em;
  color: var(--cinnabar);
}
.course-card__arrow {
  font-size: 1.1rem;
  color: var(--cinnabar);
  transition: transform 0.3s;
}
.course-card:hover .course-card__arrow { transform: translateX(4px); }

/* ================================================================
   大师 - 赵汝飞
   ================================================================ */
.master {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 3rem;
  align-items: center;
}
.master__portrait {
  position: relative;
  aspect-ratio: 3 / 4;
  background: var(--paper-deep);
  border: 1px solid var(--ink);
  overflow: hidden;
}
.master__portrait::before {
  content: '';
  position: absolute;
  inset: 8px;
  border: 1px solid var(--line);
}
.master__portrait-char {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: var(--font-brush);
  font-size: clamp(8rem, 22vw, 16rem);
  color: var(--ink);
  letter-spacing: 0.05em;
  background: linear-gradient(180deg, var(--paper) 0%, var(--paper-deep) 100%);
}
.master__portrait-name {
  position: absolute;
  bottom: 1rem;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--font-brush);
  font-size: 1.4rem;
  letter-spacing: 0.4em;
  color: var(--ink);
  padding-left: 0.4em;
}
.master__portrait-seal {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: var(--cinnabar);
  color: var(--paper);
  font-family: var(--font-brush);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  padding: 0.4rem 0.5rem;
  writing-mode: vertical-rl;
  transform: rotate(2deg);
}
.master__bio h3 {
  font-family: var(--font-brush);
  font-size: 2rem;
  margin-bottom: 0.4rem;
}
.master__bio-title {
  font-family: var(--font-deco);
  font-size: 0.85rem;
  letter-spacing: 0.32em;
  color: var(--cinnabar);
  margin-bottom: 1.6rem;
}
.master__bio p {
  font-size: 0.94rem;
  line-height: 2;
  color: var(--ink-soft);
  text-indent: 2em;
}
.master__pillars {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.8rem;
  margin-top: 1.6rem;
  padding-top: 1.6rem;
  border-top: 1px solid var(--line);
}
.master__pillar {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 0.4rem;
}
.master__pillar-char {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  font-family: var(--font-brush);
  font-size: 1.6rem;
  color: var(--paper);
  background: var(--ink);
  border-radius: 50%;
}
.master__pillar-label {
  font-size: 0.78rem;
  color: var(--ink-soft);
  letter-spacing: 0.05em;
  line-height: 1.6;
}
@media (max-width: 540px) {
  .master__pillars { grid-template-columns: repeat(2, 1fr); gap: 1rem; }
}

/* ================================================================
   时间线
   ================================================================ */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 32px;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 1px;
  background: linear-gradient(var(--cinnabar), var(--line) 80%);
}
.timeline__item {
  position: relative;
  padding-bottom: 2.2rem;
}
.timeline__item:last-child { padding-bottom: 0; }
.timeline__dot {
  position: absolute;
  left: -28px;
  top: 0.3rem;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--paper);
  border: 1.5px solid var(--cinnabar);
  z-index: 1;
}
.timeline__dot::after {
  content: '';
  position: absolute;
  inset: 3px;
  border-radius: 50%;
  background: var(--cinnabar);
  opacity: 0;
  transform: scale(0);
  transition: all 0.4s;
}
.timeline__item.is-show .timeline__dot::after { opacity: 1; transform: scale(1); }
.timeline__year {
  font-family: var(--font-num);
  font-size: 1.6rem;
  color: var(--cinnabar);
  line-height: 1;
}
.timeline__title {
  font-family: var(--font-brush);
  font-size: 1.3rem;
  margin: 0.5rem 0 0.4rem;
  letter-spacing: 0.08em;
}
.timeline__desc {
  font-size: 0.88rem;
  color: var(--ink-soft);
  line-height: 1.9;
}

/* ================================================================
   作品长廊
   ================================================================ */
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 1rem;
}
.gallery__item {
  background: var(--paper);
  border: 1px solid var(--line);
  aspect-ratio: 3 / 4;
  position: relative;
  overflow: hidden;
  cursor: pointer;
  transition: all 0.4s cubic-bezier(0.3, 0.7, 0.3, 1);
}
.gallery__item::before {
  content: '';
  position: absolute;
  inset: 6px;
  border: 1px solid var(--line);
  pointer-events: none;
}
.gallery__item:hover {
  transform: translateY(-4px) rotate(-0.5deg);
  box-shadow: var(--shadow);
}
.gallery__char {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: var(--font-brush);
  font-size: clamp(5rem, 14vw, 9rem);
  color: var(--ink);
  letter-spacing: 0;
  transition: transform 0.4s;
}
.gallery__item:hover .gallery__char { transform: scale(1.08); }
.gallery__seal {
  position: absolute;
  top: 0.8rem;
  right: 0.8rem;
  background: var(--cinnabar);
  color: var(--paper);
  font-family: var(--font-brush);
  font-size: 0.7rem;
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  transform: rotate(-3deg);
}
.gallery__info {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 0.8rem 1rem;
  background: linear-gradient(transparent, rgba(26, 29, 31, 0.85));
  color: var(--paper);
  transform: translateY(100%);
  transition: transform 0.4s cubic-bezier(0.3, 0.7, 0.3, 1);
}
.gallery__item:hover .gallery__info { transform: translateY(0); }
.gallery__author {
  font-size: 0.85rem;
  letter-spacing: 0.1em;
}
.gallery__meta {
  font-size: 0.7rem;
  color: rgba(243, 236, 217, 0.65);
  letter-spacing: 0.1em;
  margin-top: 0.2rem;
}
.gallery__score {
  position: absolute;
  bottom: 0.6rem;
  left: 0.8rem;
  font-family: var(--font-num);
  font-size: 0.9rem;
  color: var(--cinnabar);
  letter-spacing: 0.1em;
  transition: opacity 0.4s;
}
.gallery__item:hover .gallery__score { opacity: 0; }

/* ================================================================
   学员墨迹 / Gallery Item (多样化版本)
   ================================================================ */
.gw {
  position: relative;
  display: flex;
  flex-direction: column;
  transition: transform 0.45s cubic-bezier(0.3, 0.7, 0.3, 1);
  cursor: pointer;
}
.gw:hover {
  transform: rotate(0deg) translateY(-4px) !important;
  z-index: 2;
}
.gw__paper {
  position: relative;
  aspect-ratio: 3 / 4;
  background: var(--gw-bg, var(--paper));
  border: 1px solid var(--ink);
  overflow: hidden;
  box-shadow: 0 6px 18px -10px rgba(26,29,31,0.35);
  background-image:
    radial-gradient(var(--gw-tint, transparent) 1px, transparent 1px),
    radial-gradient(var(--gw-tint, transparent) 1px, transparent 1px);
  background-size: 4px 4px, 11px 11px;
  background-position: 0 0, 2px 3px;
}
.gw__paper::before {
  content: '';
  position: absolute;
  inset: 8px;
  border: 1px solid rgba(26,29,31,0.18);
  pointer-events: none;
}
.gw__paper::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 30% 30%, rgba(26,29,31,0.04), transparent 50%),
    radial-gradient(ellipse at 70% 70%, rgba(26,29,31,0.05), transparent 55%);
  pointer-events: none;
}
.gw__ink-blot {
  position: absolute;
  width: 60%;
  height: 60%;
  top: 20%;
  left: 20%;
  background: radial-gradient(circle, rgba(26,29,31,0.04), transparent 70%);
  pointer-events: none;
  filter: blur(2px);
}
.gw__single {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-size: calc(clamp(5rem, 14vw, 9.5rem) * var(--gw-size, 1));
  color: var(--ink);
  line-height: 1;
  transition: transform 0.45s;
}
.gw__vert {
  position: absolute;
  inset: 14% 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-around;
  gap: 0.1em;
  font-size: calc(clamp(2.4rem, 7vw, 4.6rem) * var(--gw-size, 1));
  color: var(--ink);
  line-height: 1;
  letter-spacing: 0;
}
.gw__vert span {
  display: block;
}
.gw:hover .gw__single { transform: scale(1.05); }
.gw__seal {
  position: absolute;
  top: 12px;
  right: 12px;
  background: var(--cinnabar);
  color: var(--paper);
  font-family: var(--font-brush);
  font-size: 0.78rem;
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  transform: rotate(-3deg);
  box-shadow: 0 1px 4px -1px rgba(168,50,45,0.4);
}
.gw__plate {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.5rem 0.2rem 0;
  font-size: 0.78rem;
}
.gw__author {
  font-family: var(--font-deco);
  letter-spacing: 0.16em;
  color: var(--ink);
}
.gw__style {
  font-family: var(--font-brush);
  font-size: 0.85rem;
  color: var(--ink-light);
  letter-spacing: 0.1em;
}
@media (max-width: 480px) {
  .gal-grid { grid-template-columns: repeat(2, 1fr) !important; }
}

/* ================================================================
   数据 / 统计
   ================================================================ */
.stats {
  background: var(--ink);
  color: var(--paper);
  padding: 4rem 1.2rem;
  position: relative;
  overflow: hidden;
}
.stats::before {
  content: '壹';
  position: absolute;
  top: -2rem;
  left: 2rem;
  font-family: var(--font-brush);
  font-size: 16rem;
  color: rgba(243, 236, 217, 0.04);
  pointer-events: none;
}
.stats__inner {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 2rem;
  position: relative;
}
.stat-item {
  text-align: center;
}
.stat-item__num {
  font-family: var(--font-num);
  font-size: 3.4rem;
  color: var(--paper);
  line-height: 1;
}
.stat-item__num sup {
  font-size: 0.4em;
  color: var(--cinnabar);
  margin-left: 4px;
}
.stat-item__label {
  font-size: 0.78rem;
  letter-spacing: 0.5em;
  color: rgba(243, 236, 217, 0.6);
  margin-top: 0.8rem;
  padding-left: 0.5em;
}

/* ================================================================
   留言 / 学员心声
   ================================================================ */
.voices {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.4rem;
}
.voice-card {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 1.6rem 1.4rem;
  position: relative;
}
.voice-card::before {
  content: '"';
  position: absolute;
  top: -0.5rem;
  left: 0.6rem;
  font-family: var(--font-brush);
  font-size: 3.6rem;
  color: var(--paper-deep);
  line-height: 1;
}
.voice-card__content {
  font-size: 0.9rem;
  line-height: 2;
  color: var(--ink-soft);
  position: relative;
  z-index: 1;
}
.voice-card__foot {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px dashed var(--line);
  font-size: 0.78rem;
}
.voice-card__name {
  font-family: var(--font-brush);
  font-size: 1.05rem;
  letter-spacing: 0.12em;
}
.voice-card__city {
  color: var(--ink-light);
  letter-spacing: 0.2em;
}

.voice-form {
  margin-top: 2.4rem;
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 1.6rem;
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr 1fr 2fr auto;
  align-items: end;
}
.voice-form__field { display: flex; flex-direction: column; gap: 0.4rem; }
.voice-form__field label {
  font-size: 0.74rem;
  letter-spacing: 0.3em;
  color: var(--ink-light);
}
.voice-form input, .voice-form textarea {
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--line);
  padding: 0.5rem 0;
  font-family: var(--font-serif);
  font-size: 0.95rem;
  color: var(--ink);
  outline: none;
  width: 100%;
  resize: none;
}
.voice-form input:focus, .voice-form textarea:focus { border-bottom-color: var(--cinnabar); }

/* ================================================================
   报名表单
   ================================================================ */
.enroll {
  background: linear-gradient(180deg, var(--paper) 0%, var(--paper-deep) 100%);
  padding: 5rem 1.2rem;
  position: relative;
}
.enroll__inner {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
}
.enroll__form {
  margin-top: 2.4rem;
  background: var(--paper);
  border: 1px solid var(--ink);
  padding: 2rem;
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr 1fr;
  text-align: left;
  position: relative;
}
.enroll__form::before, .enroll__form::after {
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  border-color: var(--cinnabar);
  border-style: solid;
}
.enroll__form::before { top: -1px; left: -1px; border-width: 1px 0 0 1px; }
.enroll__form::after { bottom: -1px; right: -1px; border-width: 0 1px 1px 0; }
.enroll__field { display: flex; flex-direction: column; gap: 0.4rem; }
.enroll__field--full { grid-column: 1 / -1; }
.enroll__field label {
  font-size: 0.78rem;
  letter-spacing: 0.3em;
  color: var(--ink-soft);
}
.enroll__field label .req { color: var(--cinnabar); }
.enroll__field input, .enroll__field select, .enroll__field textarea {
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--line);
  padding: 0.55rem 0;
  font-family: var(--font-serif);
  font-size: 0.95rem;
  color: var(--ink);
  outline: none;
  transition: border-color 0.3s;
}
.enroll__field input:focus, .enroll__field select:focus, .enroll__field textarea:focus { border-bottom-color: var(--cinnabar); }
.enroll__submit {
  grid-column: 1 / -1;
  display: flex;
  justify-content: center;
  margin-top: 0.6rem;
}
.enroll__msg {
  grid-column: 1 / -1;
  text-align: center;
  font-size: 0.9rem;
  color: var(--cinnabar);
  min-height: 1.2em;
  margin-top: 0.6rem;
}

/* ================================================================
   底部
   ================================================================ */
.footer {
  background: var(--ink);
  color: rgba(243, 236, 217, 0.7);
  padding: 4rem 1.2rem 2rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.footer::before {
  content: '墨';
  position: absolute;
  bottom: -4rem;
  right: -1rem;
  font-family: var(--font-brush);
  font-size: 16rem;
  color: rgba(243, 236, 217, 0.04);
  pointer-events: none;
}
.footer__brand {
  font-family: var(--font-brush);
  font-size: 1.8rem;
  letter-spacing: 0.3em;
  color: var(--paper);
  padding-left: 0.3em;
}
.footer__slogan {
  font-family: var(--font-deco);
  font-size: 0.85rem;
  letter-spacing: 0.5em;
  color: rgba(243, 236, 217, 0.5);
  margin: 1rem 0 2rem;
  padding-left: 0.5em;
}
.footer__columns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 2rem;
  text-align: left;
  max-width: 900px;
  margin: 0 auto 2rem;
  padding: 2rem 0;
  border-top: 1px solid rgba(243, 236, 217, 0.1);
  border-bottom: 1px solid rgba(243, 236, 217, 0.1);
}
.footer__col-title {
  font-family: var(--font-brush);
  font-size: 1.05rem;
  letter-spacing: 0.2em;
  color: var(--paper);
  margin-bottom: 1rem;
}
.footer__col-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.footer__col-list li {
  font-size: 0.82rem;
  letter-spacing: 0.1em;
  color: rgba(243, 236, 217, 0.6);
}
.footer__copy {
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: rgba(243, 236, 217, 0.4);
  margin-top: 1.5rem;
}

/* ================================================================
   动画关键帧
   ================================================================ */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes charDrop {
  to { opacity: 1; transform: translateY(0) rotate(0); }
}
@keyframes sealStamp {
  0% { opacity: 0; transform: rotate(-3deg) scale(2); }
  60% { opacity: 1; transform: rotate(-3deg) scale(0.9); }
  100% { opacity: 1; transform: rotate(-3deg) scale(1); }
}

.dot-loader {
  display: inline-block;
  width: 18px;
  height: 4px;
  background:
    radial-gradient(circle, var(--cinnabar) 40%, transparent 41%) 0 50% / 4px 4px no-repeat,
    radial-gradient(circle, var(--cinnabar) 40%, transparent 41%) 7px 50% / 4px 4px no-repeat,
    radial-gradient(circle, var(--cinnabar) 40%, transparent 41%) 14px 50% / 4px 4px no-repeat;
  animation: dotLoader 1.1s infinite;
}
@keyframes dotLoader {
  0%, 80%, 100% { opacity: 0.3; }
  40% { opacity: 1; }
}

.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.9s cubic-bezier(0.3, 0.7, 0.3, 1), transform 0.9s cubic-bezier(0.3, 0.7, 0.3, 1);
}
.reveal.is-show { opacity: 1; transform: translateY(0); }
.reveal--delay-1 { transition-delay: 0.1s; }
.reveal--delay-2 { transition-delay: 0.2s; }
.reveal--delay-3 { transition-delay: 0.3s; }
.reveal--delay-4 { transition-delay: 0.4s; }

/* ================================================================
   响应式
   ================================================================ */
@media (max-width: 880px) {
  html { font-size: 14.5px; }
  .nav__menu { display: none; }
  .nav__cta { display: none; }
  .nav__burger { display: block; }
  .nav__menu.is-open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(243, 236, 217, 0.98);
    padding: 1.5rem 1.2rem;
    border-bottom: 1px solid var(--line);
    gap: 1.2rem;
  }
  .nav__menu.is-open a {
    font-size: 1.05rem;
    letter-spacing: 0.18em;
    padding: 0.4rem 0;
    border-bottom: 1px solid var(--line-soft);
  }
  .hero { padding: 6rem 1rem 3rem; min-height: 92vh; }
  .hero__couplet { display: none; }
  .hero__divider { margin: 1.2rem auto; }
  .hero__cta { flex-direction: column; align-items: stretch; width: 70%; margin-left: auto; margin-right: auto; }
  .btn { justify-content: center; }
  .section { padding: 4.5rem 1rem 3rem; }
  .section__num { font-size: 4rem; }
  .section__title { font-size: 1.8rem; margin-top: -2.2rem; }
  .experience { padding: 4rem 1rem; }
  .experience__inner { grid-template-columns: 1fr; gap: 2rem; }
  .master { grid-template-columns: 1fr; gap: 2rem; }
  .master__portrait { max-width: 320px; margin: 0 auto; }
  .stats__inner { gap: 1.5rem; grid-template-columns: repeat(2, 1fr); }
  .stat-item__num { font-size: 2.6rem; }
  .voice-form {
    grid-template-columns: 1fr;
  }
  .enroll__form { grid-template-columns: 1fr; padding: 1.5rem; }
  .footer__columns { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 480px) {
  .hero__title { font-size: 3rem; letter-spacing: 0.04em; }
  .section__title { font-size: 1.55rem; }
  .gallery { grid-template-columns: repeat(2, 1fr); }
  .stats__inner { gap: 1.2rem; }
  .stat-item__num { font-size: 2.2rem; }
  .stat-item__label { letter-spacing: 0.3em; font-size: 0.7rem; }
}