/* ========================
   如是花开 · 东方唯美风格
   ======================== */

:root {
  --ink: #0f172a;
  --ink-light: #1e293b;
  --gold: #d4af37;
  --gold-light: #f0d878;
  --gold-dim: #a0822a;
  --cream: #faf8f3;
  --cream-dark: #f2efe6;
  --vermilion: #a83f39;
  --vermilion-light: #c9544d;
  --text-main: #334155;
  --text-light: #f8fafc;
  --shadow: 0 10px 40px rgba(15, 23, 42, 0.12);
  --radius: 16px;
  --transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  color: var(--text-main);
  background: var(--cream);
  line-height: 1.85;
  overflow-x: hidden;
}

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

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

.container {
  width: min(92%, 1120px);
  margin: 0 auto;
}

.section {
  padding: 100px 0;
  position: relative;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header.light {
  color: var(--text-light);
}

.section-tag {
  display: inline-block;
  font-size: 0.85rem;
  letter-spacing: 0.25em;
  color: var(--gold);
  margin-bottom: 12px;
  text-transform: uppercase;
}

.section-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 600;
  color: var(--ink);
  position: relative;
  display: inline-block;
  padding-bottom: 16px;
}

.section-header.light .section-title {
  color: var(--text-light);
}

.section-title::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  border-radius: 2px;
}

.section-desc {
  margin-top: 18px;
  font-size: 1.05rem;
  opacity: 0.85;
}

/* 飘落花瓣 */
.petals {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.petal {
  position: absolute;
  top: -10%;
  width: 12px;
  height: 12px;
  background: linear-gradient(135deg, var(--gold-light), var(--gold-dim));
  border-radius: 50% 0 50% 50%;
  opacity: 0.45;
  animation: fall linear infinite;
}

@keyframes fall {
  0% {
    transform: translateY(0) rotate(0deg) translateX(0);
    opacity: 0;
  }
  10% {
    opacity: 0.45;
  }
  90% {
    opacity: 0.35;
  }
  100% {
    transform: translateY(110vh) rotate(720deg) translateX(40px);
    opacity: 0;
  }
}

/* 导航 */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(212, 175, 55, 0.15);
  transition: var(--transition);
}

.nav-inner {
  width: min(92%, 1120px);
  margin: 0 auto;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: flex-start;
}

.nav-menu {
  margin-left: auto;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-light);
}

.nav-logo .seal {
  width: 38px;
  height: 38px;
  border: 2px solid var(--gold);
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-family: "Zhi Mang Xing", cursive;
  font-size: 1.3rem;
  color: var(--gold);
}

.nav-title {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: 0.12em;
}

.nav-menu {
  display: flex;
  gap: 36px;
  list-style: none;
}

.nav-menu a {
  color: var(--cream);
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  position: relative;
  padding: 6px 0;
  transition: var(--transition);
}

.nav-menu a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--gold);
  transition: var(--transition);
}

.nav-menu a:hover {
  color: var(--gold);
}

.nav-menu a:hover::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 26px;
  height: 2px;
  background: var(--gold);
  transition: var(--transition);
}

/* 首页 Hero */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
  background: var(--ink);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 30% 20%, rgba(212, 175, 55, 0.12) 0%, transparent 45%),
    radial-gradient(circle at 70% 80%, rgba(168, 63, 57, 0.08) 0%, transparent 40%),
    linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
}

.hero-bg::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23d4af37' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.6;
}

.hero-content {
  position: relative;
  z-index: 2;
  padding: 0 20px;
  animation: fadeInUp 1.2s ease-out;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-subtitle {
  font-size: 1.1rem;
  letter-spacing: 0.5em;
  color: var(--gold);
  margin-bottom: 20px;
  text-transform: uppercase;
}

.hero-title {
  font-family: "Zhi Mang Xing", cursive;
  font-size: clamp(4rem, 14vw, 9rem);
  color: var(--text-light);
  line-height: 1.1;
  margin-bottom: 24px;
  text-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

.hero-motto {
  font-size: clamp(1.1rem, 3vw, 1.6rem);
  color: var(--gold);
  letter-spacing: 0.2em;
  margin-bottom: 20px;
}

.hero-motto .dot {
  margin: 0 10px;
  opacity: 0.6;
}

.hero-author {
  color: var(--cream);
  opacity: 0.7;
  letter-spacing: 0.15em;
  margin-bottom: 40px;
}

.hero-cta {
  display: inline-block;
  padding: 16px 44px;
  border: 1.5px solid var(--gold);
  color: var(--gold);
  font-size: 1rem;
  letter-spacing: 0.15em;
  border-radius: 999px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.hero-cta::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.5s ease;
  z-index: -1;
}

.hero-cta:hover {
  color: var(--ink);
}

.hero-cta:hover::before {
  transform: scaleX(1);
  transform-origin: left;
}

.hero-scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--gold);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  opacity: 0.5;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-10px); }
  60% { transform: translateX(-50%) translateY(-5px); }
}

/* 课程宗旨 */
.purpose {
  background: var(--cream);
}

.purpose-grid {
  display: grid;
  gap: 30px;
  grid-template-columns: 1fr;
}

.purpose-card {
  background: #fff;
  padding: 44px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid rgba(212, 175, 55, 0.12);
  position: relative;
}

.purpose-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--gold), var(--vermilion));
  border-radius: var(--radius) var(--radius) 0 0;
}

.purpose-card h3 {
  font-size: 1.5rem;
  color: var(--ink);
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.purpose-card h3::before {
  content: "❖";
  color: var(--gold);
  font-size: 1.1rem;
}

.purpose-card p {
  margin-bottom: 16px;
  text-align: justify;
}

.purpose-card p:last-child {
  margin-bottom: 0;
}

.centered {
  text-align: center;
}

.purpose-card .lead-quote {
  font-size: 1.25rem;
  color: var(--ink);
  line-height: 2;
  letter-spacing: 0.05em;
  text-align: center;
  padding: 24px;
  background: linear-gradient(135deg, rgba(212, 175, 55, 0.06), rgba(168, 63, 57, 0.04));
  border-radius: 12px;
  border-left: 3px solid var(--gold);
}

.aims-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.aim-item {
  text-align: center;
  padding: 24px;
  background: var(--cream);
  border-radius: 12px;
}

.aim-icon {
  display: block;
  width: 48px;
  height: 48px;
  margin: 0 auto 14px;
  border: 1.5px solid var(--gold);
  border-radius: 50%;
  display: grid;
  place-items: center;
  color: var(--gold);
  font-weight: 600;
  font-size: 1.1rem;
}

.aim-item strong {
  display: block;
  color: var(--ink);
  margin-bottom: 8px;
  font-size: 1.05rem;
}

.aim-item p {
  font-size: 0.95rem;
  margin-bottom: 0;
}

/* 21天课程表 */
.schedule {
  background: var(--ink);
  position: relative;
}

.schedule::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M11 18c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm48 25c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm-43-7c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm63 31c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM34 90c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm56-76c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM12 86c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm28-65c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm23-11c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-6 60c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm29 22c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zM32 63c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm57-13c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-9-21c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM60 91c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM35 41c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM12 60c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2z' fill='%23d4af37' fill-opacity='0.03' fill-rule='evenodd'/%3E%3C/svg%3E");
}

.weeks {
  display: flex;
  flex-direction: column;
  gap: 50px;
  position: relative;
  z-index: 1;
}

.week {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(212, 175, 55, 0.18);
  border-radius: var(--radius);
  padding: 36px;
  backdrop-filter: blur(4px);
}

.week-header {
  display: flex;
  align-items: flex-start;
  gap: 24px;
  margin-bottom: 28px;
  padding-bottom: 24px;
  border-bottom: 1px solid rgba(212, 175, 55, 0.15);
}

.week-number {
  font-family: "Zhi Mang Xing", cursive;
  font-size: 3.5rem;
  color: var(--gold);
  line-height: 1;
  opacity: 0.9;
}

.week-header h3 {
  font-size: 1.6rem;
  color: var(--gold);
  margin-bottom: 8px;
}

.week-header p {
  color: var(--cream);
  opacity: 0.75;
  font-size: 0.98rem;
}

.days {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 18px;
}

.day {
  background: rgba(30, 41, 59, 0.6);
  border: 1px solid rgba(212, 175, 55, 0.12);
  border-radius: 12px;
  padding: 22px;
  display: flex;
  gap: 16px;
  transition: var(--transition);
}

.day:hover {
  transform: translateY(-4px);
  border-color: rgba(212, 175, 55, 0.35);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
}

.day-number {
  font-family: "Zhi Mang Xing", cursive;
  font-size: 2rem;
  color: var(--gold);
  line-height: 1;
  opacity: 0.85;
}

.day-content h4 {
  color: var(--cream);
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.day-content p {
  color: var(--cream);
  opacity: 0.65;
  font-size: 0.92rem;
  line-height: 1.7;
}

.day.rest {
  border-style: dashed;
  opacity: 0.8;
}

.day.rest .day-number {
  color: var(--vermilion-light);
}

.day.final {
  border-color: var(--gold);
  background: rgba(212, 175, 55, 0.08);
}

.day.final .day-number {
  color: var(--gold-light);
}

/* 核心理念 */
.core {
  background: var(--cream);
}

.core-tabs {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.core-tab {
  padding: 12px 28px;
  border: 1px solid var(--gold-dim);
  background: transparent;
  color: var(--ink);
  font-family: inherit;
  font-size: 1rem;
  cursor: pointer;
  border-radius: 999px;
  transition: var(--transition);
}

.core-tab:hover {
  border-color: var(--gold);
  color: var(--gold-dim);
}

.core-tab.active {
  background: var(--ink);
  color: var(--gold);
  border-color: var(--ink);
}

.core-panels {
  position: relative;
  min-height: 320px;
}

.core-panel {
  display: none;
  background: #fff;
  padding: 44px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid rgba(212, 175, 55, 0.12);
  animation: fadeIn 0.5s ease;
}

.core-panel.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.core-panel h3 {
  font-size: 1.5rem;
  color: var(--ink);
  margin-bottom: 24px;
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(212, 175, 55, 0.2);
}

.core-panel h4 {
  font-size: 1.15rem;
  color: var(--vermilion);
  margin: 28px 0 14px;
}

.core-panel p {
  margin-bottom: 16px;
  text-align: justify;
}

.core-panel blockquote {
  border-left: 3px solid var(--gold);
  padding-left: 20px;
  margin: 18px 0;
  color: var(--ink-light);
  font-style: italic;
  background: var(--cream-dark);
  padding: 16px 20px;
  border-radius: 0 8px 8px 0;
}

.ask-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  margin: 18px 0;
}

.ask-list p {
  background: var(--cream);
  padding: 12px 18px;
  border-radius: 8px;
  margin: 0;
  border-left: 3px solid var(--gold);
}

.virtue-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}

.virtue-list li {
  background: var(--cream);
  padding: 14px 18px;
  border-radius: 8px;
}

.extra-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
  margin-top: 50px;
}

.extra-card {
  background: #fff;
  padding: 34px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid rgba(212, 175, 55, 0.12);
}

.extra-card h4 {
  color: var(--ink);
  font-size: 1.25rem;
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.extra-card h4::before {
  content: "◈";
  color: var(--gold);
}

.extra-card ol {
  padding-left: 22px;
}

.extra-card li {
  margin-bottom: 8px;
}

.extra-card p {
  margin-bottom: 12px;
}

.extra-card.poem {
  background: var(--ink);
  color: var(--cream);
}

.extra-card.poem h4 {
  color: var(--gold);
}

.extra-card.poem p {
  line-height: 2.2;
  letter-spacing: 0.05em;
}

/* 自我探索 */
.explore {
  background:
    linear-gradient(135deg, rgba(15, 23, 42, 0.96) 0%, rgba(30, 41, 59, 0.95) 100%),
    url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23d4af37' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.explore-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.explore-item {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(212, 175, 55, 0.15);
  border-radius: 12px;
  padding: 26px;
  display: flex;
  align-items: center;
  gap: 18px;
  transition: var(--transition);
}

.explore-item:hover {
  background: rgba(212, 175, 55, 0.08);
  transform: translateY(-3px);
}

.explore-item span {
  font-family: "Zhi Mang Xing", cursive;
  font-size: 2rem;
  color: var(--gold);
  opacity: 0.8;
  min-width: 36px;
}

.explore-item p {
  color: var(--cream);
  font-size: 1.05rem;
  margin: 0;
}

/* Ai歌曲 */
.song {
  background: var(--cream);
}

.song-card {
  max-width: 680px;
  margin: 0 auto;
  background: var(--ink);
  padding: 56px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}

.song-card::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(212, 175, 55, 0.1) 0%, transparent 70%);
  border-radius: 50%;
}

.song-lyrics {
  position: relative;
  z-index: 1;
  text-align: center;
  color: var(--cream);
  font-size: 1.1rem;
  line-height: 2.2;
}

.song-lyrics p {
  margin-bottom: 6px;
}

.song-lyrics .highlight {
  color: var(--gold);
  font-weight: 600;
  letter-spacing: 0.08em;
}

/* 作业与反思 */
.homework {
  background: var(--ink);
}

.homework-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-bottom: 40px;
}

.homework-card {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(212, 175, 55, 0.15);
  border-radius: var(--radius);
  padding: 34px;
  color: var(--cream);
}

.homework-card.wide {
  grid-column: 1 / -1;
}

.homework-card h3 {
  color: var(--gold);
  font-size: 1.3rem;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.homework-card h3::before {
  content: "✦";
  font-size: 0.9rem;
}

.homework-card p,
.homework-card li {
  opacity: 0.85;
  margin-bottom: 10px;
}

.homework-card ol {
  padding-left: 22px;
}

.architecture {
  display: grid;
  gap: 12px;
}

.architecture p {
  background: rgba(212, 175, 55, 0.06);
  padding: 14px 18px;
  border-radius: 8px;
  margin: 0;
  border-left: 2px solid var(--gold);
}

.homework-images {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.homework-images figure {
  margin: 0;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid rgba(212, 175, 55, 0.15);
}

.homework-images img {
  width: 100%;
  height: auto;
  display: block;
}

.homework-images figcaption {
  text-align: center;
  padding: 14px;
  color: var(--gold);
  background: rgba(255, 255, 255, 0.03);
  font-size: 0.95rem;
}

/* 页脚 */
.footer {
  background: #070c18;
  padding: 70px 0 50px;
  text-align: center;
  color: var(--cream);
  border-top: 1px solid rgba(212, 175, 55, 0.12);
}

.footer-seal {
  width: 64px;
  height: 64px;
  border: 2px solid var(--gold);
  border-radius: 50%;
  display: grid;
  place-items: center;
  margin: 0 auto 24px;
  font-family: "Zhi Mang Xing", cursive;
  font-size: 2rem;
  color: var(--gold);
}

.footer-quote {
  font-size: 1.4rem;
  color: var(--gold);
  letter-spacing: 0.15em;
  margin-bottom: 12px;
}

.footer-copy {
  opacity: 0.55;
  font-size: 0.9rem;
}

/* 回到顶部 */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 48px;
  height: 48px;
  border: 1.5px solid var(--gold);
  border-radius: 50%;
  display: grid;
  place-items: center;
  color: var(--gold);
  font-size: 1.2rem;
  background: rgba(15, 23, 42, 0.8);
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--gold);
  color: var(--ink);
}

/* 响应式 */
@media (max-width: 900px) {
  .section {
    padding: 70px 0;
  }

  .aims-row {
    grid-template-columns: 1fr;
  }

  .homework-grid,
  .homework-images {
    grid-template-columns: 1fr;
  }

  .homework-card.wide {
    grid-column: auto;
  }

  .nav-menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: rgba(15, 23, 42, 0.97);
    flex-direction: column;
    align-items: center;
    padding: 24px 0 36px;
    gap: 0;
    transform: translateY(-150%);
    transition: var(--transition);
    border-bottom: 1px solid rgba(212, 175, 55, 0.15);
  }

  .nav-menu.open {
    transform: translateY(0);
  }

  .nav-menu li {
    width: 100%;
    text-align: center;
  }

  .nav-menu a {
    display: block;
    padding: 14px 0;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav-toggle.active span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }
}

@media (max-width: 600px) {
  .hero-title {
    font-size: 4.2rem;
  }

  .purpose-card,
  .core-panel,
  .song-card,
  .homework-card,
  .week {
    padding: 28px;
  }

  .week-header {
    flex-direction: column;
    gap: 14px;
  }

  .core-tabs {
    gap: 8px;
  }

  .core-tab {
    padding: 10px 18px;
    font-size: 0.9rem;
  }

  .day {
    flex-direction: column;
    gap: 10px;
  }

  .extra-cards {
    grid-template-columns: 1fr;
  }
}

/* 导航当前项高亮 */
.nav-menu a.active {
  color: var(--gold);
}

.nav-menu a.active::after {
  width: 100%;
}

/* ========================
   登录注册与学员系统
   ======================== */

.nav-auth {
  display: flex;
  align-items: center;
  margin-left: 24px;
}

.auth-btn {
  padding: 8px 20px;
  border: 1.5px solid var(--gold);
  background: transparent;
  color: var(--gold);
  font-family: inherit;
  font-size: 0.9rem;
  border-radius: 999px;
  cursor: pointer;
  transition: var(--transition);
}

.auth-btn:hover {
  background: var(--gold);
  color: var(--ink);
}

.auth-btn.logout {
  margin-left: 12px;
  padding: 6px 14px;
  font-size: 0.8rem;
}

.user-info {
  display: flex;
  align-items: center;
  color: var(--cream);
  font-size: 0.9rem;
}

.user-info span {
  max-width: 120px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.hidden {
  display: none !important;
}

/* 模态框 */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  padding: 20px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.modal-overlay:not(.hidden) {
  opacity: 1;
  visibility: visible;
}

.modal {
  background: var(--cream);
  border-radius: var(--radius);
  width: min(100%, 480px);
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
  border: 1px solid rgba(212, 175, 55, 0.25);
  position: relative;
  animation: modalIn 0.35s ease;
}

.day-modal {
  width: min(100%, 640px);
}

@keyframes modalIn {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 20px;
  background: none;
  border: none;
  font-size: 1.8rem;
  color: var(--ink);
  cursor: pointer;
  line-height: 1;
  z-index: 10;
}

.modal-close:hover {
  color: var(--vermilion);
}

.modal-tabs {
  display: flex;
  border-bottom: 1px solid rgba(212, 175, 55, 0.2);
}

.modal-tab {
  flex: 1;
  padding: 18px;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  font-family: inherit;
  font-size: 1rem;
  color: var(--text-main);
  cursor: pointer;
  transition: var(--transition);
}

.modal-tab:hover {
  color: var(--gold-dim);
}

.modal-tab.active {
  color: var(--gold);
  border-bottom-color: var(--gold);
  font-weight: 600;
}

.modal-panel {
  display: none;
  padding: 32px;
}

.modal-panel.active {
  display: block;
}

.modal-panel h3 {
  font-size: 1.4rem;
  color: var(--ink);
  margin-bottom: 24px;
  text-align: center;
}

.form-group {
  margin-bottom: 18px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  color: var(--ink);
  font-size: 0.95rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid rgba(212, 175, 55, 0.3);
  border-radius: 10px;
  background: #fff;
  font-family: inherit;
  font-size: 1rem;
  color: var(--ink);
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--gold);
  box-shadow: 0 0 0 3px rgba(212, 175, 55, 0.1);
}

.form-error {
  color: var(--vermilion);
  font-size: 0.9rem;
  margin-bottom: 16px;
  min-height: 1.4em;
}

.submit-btn {
  width: 100%;
  padding: 14px;
  background: var(--ink);
  color: var(--gold);
  border: none;
  border-radius: 10px;
  font-family: inherit;
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
}

.submit-btn:hover {
  background: var(--gold);
  color: var(--ink);
}

/* 课程详情模态框 */
.day-modal-header {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 32px 32px 20px;
  border-bottom: 1px solid rgba(212, 175, 55, 0.15);
  background: linear-gradient(135deg, rgba(212, 175, 55, 0.05), rgba(168, 63, 57, 0.03));
}

.day-modal-number {
  font-family: "Zhi Mang Xing", cursive;
  font-size: 3rem;
  color: var(--gold);
  line-height: 1;
}

.day-modal-header h3 {
  font-size: 1.5rem;
  color: var(--ink);
  margin-bottom: 8px;
}

.day-modal-header p {
  color: var(--text-main);
  opacity: 0.8;
  line-height: 1.7;
}

.day-modal-body {
  padding: 28px 32px 32px;
}

.reflection-section h4 {
  font-size: 1.15rem;
  color: var(--ink);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.reflection-section h4::before {
  content: "✍";
  color: var(--gold);
}

#reflectionContent {
  width: 100%;
  padding: 16px;
  border: 1px solid rgba(212, 175, 55, 0.3);
  border-radius: 10px;
  background: #fff;
  font-family: inherit;
  font-size: 1rem;
  line-height: 1.8;
  resize: vertical;
  transition: var(--transition);
}

#reflectionContent:focus {
  outline: none;
  border-color: var(--gold);
  box-shadow: 0 0 0 3px rgba(212, 175, 55, 0.1);
}

#reflectionContent:disabled {
  background: var(--cream-dark);
  cursor: not-allowed;
}

.reflection-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 16px;
}

.reflection-actions .submit-btn {
  width: auto;
  padding: 12px 32px;
}

.reflection-status {
  color: var(--gold-dim);
  font-size: 0.9rem;
}

/* 课程卡片可点击 */
.day {
  cursor: pointer;
  position: relative;
}

.day::after {
  content: "写心得";
  position: absolute;
  top: 14px;
  right: 14px;
  font-size: 0.7rem;
  color: var(--gold);
  border: 1px solid var(--gold);
  padding: 2px 8px;
  border-radius: 999px;
  opacity: 0.6;
  transition: var(--transition);
}

.day:hover::after {
  opacity: 1;
  background: var(--gold);
  color: var(--ink);
}

.day.rest::after {
  content: "休息日";
  border-color: var(--vermilion-light);
  color: var(--vermilion-light);
}

.day.rest:hover::after {
  background: var(--vermilion-light);
  color: var(--cream);
}

/* 响应式 */
@media (max-width: 900px) {
  .nav-auth {
    margin-left: auto;
    margin-right: 16px;
  }

  .auth-btn {
    padding: 6px 14px;
    font-size: 0.8rem;
  }

  .modal {
    width: 100%;
    max-height: 85vh;
  }

  .modal-panel {
    padding: 24px;
  }

  .day-modal-header,
  .day-modal-body {
    padding-left: 24px;
    padding-right: 24px;
  }

  .reflection-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .reflection-actions .submit-btn {
    width: 100%;
  }
}