/* ===== GoAMC.cn 全站样式 ===== */
:root {
  --primary: #f97316;
  --primary-dark: #ea580c;
  --primary-light: #fff7ed;
  --accent: #ec4899;
  --accent-light: #fdf2f8;
  --amc8-color: #10b981;
  --amc10-color: #f97316;
  --amc12-color: #a855f7;
  --dark: #1e293b;
  --gray-700: #44403c;
  --gray-500: #78716c;
  --gray-300: #e7e5e4;
  --gray-100: #f5f5f4;
  --white: #ffffff;
  --warm-bg: #fffbf7;
  --warm-bg2: #fef7f0;
  --shadow-sm: 0 2px 8px rgba(0,0,0,.05);
  --shadow-md: 0 6px 24px rgba(0,0,0,.07);
  --shadow-lg: 0 12px 40px rgba(0,0,0,.09);
  --shadow-warm: 0 6px 24px rgba(249,115,22,.12);
  --radius: 16px;
  --radius-lg: 24px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: var(--dark);
  background: var(--warm-bg);
  line-height: 1.8;
  font-size: 16px;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; }

.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== HEADER ===== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(255,255,255,.96);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(0,0,0,.06);
  height: 68px;
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo a {
  display: flex;
  align-items: baseline;
  gap: 1px;
  font-size: 1.6rem;
  font-weight: 700;
}
.logo-go { color: var(--primary); }
.logo-amc { color: var(--accent); }
.logo-sub { font-size: 1rem; color: var(--gray-500); font-weight: 400; }

.nav ul {
  display: flex;
  gap: 4px;
}

.nav ul li a {
  padding: 8px 16px;
  border-radius: 10px;
  font-size: 1rem;
  font-weight: 500;
  color: var(--gray-700);
  transition: all .2s;
}

.nav ul li a:hover,
.nav ul li a.active {
  background: var(--primary-light);
  color: var(--primary);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
}
.hamburger span {
  width: 24px; height: 2px;
  background: var(--dark);
  border-radius: 2px;
  transition: .3s;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all .25s;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--primary);
  color: var(--white);
}
.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(249,115,22,.3);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border-color: var(--primary);
}
.btn-outline:hover {
  background: var(--primary-light);
  transform: translateY(-2px);
}

/* ===== SECTION COMMON ===== */
.section {
  padding: 100px 0;
}

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

.section-header h2 {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 14px;
}

.section-header p {
  font-size: 1.1rem;
  color: var(--gray-500);
}

/* ===== HERO ===== */
.hero {
  padding-top: 140px;
  padding-bottom: 100px;
  background: linear-gradient(160deg, #fff7ed 0%, #fff1eb 40%, #fef2f8 100%);
  position: relative;
  overflow: hidden;
  min-height: 100vh;
  display: flex;
  align-items: center;
}

.hero-bg {
  position: absolute;
  top: -200px; right: -200px;
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(249,115,22,.06) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

/* 底部柔光装饰 */
.hero-glow {
  position: absolute;
  bottom: -100px; left: -100px;
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(236,72,153,.06) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

/* 可爱装饰泡泡 — 精简版，只保留2个 */
.hero-deco {
  position: absolute;
  pointer-events: none;
  z-index: 0;
}
.hero-deco-bubble1 {
  width: 60px; height: 60px;
  background: radial-gradient(circle at 30% 30%, rgba(251,191,36,.3), rgba(249,115,22,.15));
  border-radius: 50%;
  top: 18%; left: 8%;
  animation: float 4s ease-in-out infinite;
}
.hero-deco-bubble2 {
  width: 40px; height: 40px;
  background: radial-gradient(circle at 30% 30%, rgba(244,114,182,.25), rgba(236,72,153,.1));
  border-radius: 50%;
  bottom: 30%; right: 10%;
  animation: float 5s ease-in-out infinite 1s;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-block;
  background: rgba(255,255,255,.7);
  backdrop-filter: blur(8px);
  color: var(--primary-dark);
  border: 1px solid rgba(249,115,22,.12);
  padding: 8px 20px;
  border-radius: 100px;
  font-size: .95rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.2;
  color: var(--dark);
  margin-bottom: 24px;
}

.hero-title .highlight {
  color: var(--primary);
  position: relative;
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--gray-700);
  margin-bottom: 40px;
  line-height: 1.9;
}

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

.hero-stats {
  display: flex;
  gap: 40px;
}

.stat {
  display: flex;
  flex-direction: column;
}

.stat-num {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.stat-label {
  font-size: .88rem;
  color: var(--gray-500);
  margin-top: 4px;
}

/* Hero Visual */
.hero-visual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.math-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  text-align: center;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--gray-300);
  transition: all .3s;
}

.math-card:hover {
  transform: translateY(-6px) scale(1.03);
  box-shadow: var(--shadow-warm);
}

.math-icon {
  font-size: 2.8rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 12px;
  font-family: 'Times New Roman', serif;
}

.math-label {
  font-size: .92rem;
  color: var(--gray-500);
  font-weight: 500;
}

.card-float { animation: float 3s ease-in-out infinite; }
.delay1 { animation-delay: .5s; }
.delay2 { animation-delay: 1s; }
.delay3 { animation-delay: 1.5s; }

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

/* ===== COMPETITIONS ===== */
.competitions { background: var(--white); }

.comp-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.comp-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  position: relative;
  box-shadow: var(--shadow-sm);
  border: 2px solid transparent;
  transition: all .3s;
}

.comp-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.amc8-card { border-top: 4px solid var(--amc8-color); }
.amc10-card { border-top: 4px solid var(--amc10-color); }
.amc12-card { border-top: 4px solid var(--amc12-color); }

.comp-card.featured {
  border: 2px solid var(--primary);
  box-shadow: var(--shadow-warm);
}

.comp-badge {
  position: absolute;
  top: 16px; right: 16px;
  background: var(--primary-light);
  color: var(--primary);
  font-size: .75rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 100px;
}

.amc8-card .comp-badge { background: #d1fae5; color: var(--amc8-color); }
.amc12-card .comp-badge { background: #ede9fe; color: var(--amc12-color); }

.comp-icon {
  font-size: 2.5rem;
  margin-bottom: 14px;
}

.comp-card h3 {
  font-size: 1.6rem;
  font-weight: 800;
  margin-bottom: 6px;
}

.amc8-card h3 { color: var(--amc8-color); }
.amc10-card h3 { color: var(--amc10-color); }
.amc12-card h3 { color: var(--amc12-color); }

.comp-target {
  font-size: .82rem;
  color: var(--gray-500);
  margin-bottom: 14px;
  font-weight: 500;
}

.comp-desc {
  font-size: .9rem;
  color: var(--gray-700);
  margin-bottom: 20px;
  line-height: 1.7;
}

.comp-topics {
  margin-bottom: 28px;
}

.comp-topics li {
  font-size: .88rem;
  color: var(--gray-700);
  padding: 4px 0;
}

/* ===== LEARNING PATH ===== */
.learning-path { background: var(--white); }

.path-steps {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
}

.path-step {
  flex: 1;
  min-width: 180px;
  max-width: 240px;
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px 24px;
  text-align: center;
  border: 1px solid var(--gray-300);
}

.step-num {
  font-size: 2.2rem;
  font-weight: 900;
  color: var(--primary);
  opacity: .3;
  margin-bottom: 8px;
}

.step-content h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 8px;
}

.step-content p {
  font-size: .85rem;
  color: var(--gray-500);
  line-height: 1.6;
}

.path-arrow {
  font-size: 1.8rem;
  color: var(--gray-300);
  font-weight: 300;
  flex-shrink: 0;
}

/* ===== FEATURES ===== */
.features { background: var(--warm-bg); }

.section-sep {
  height: 1px;
  background: var(--gray-300);
  opacity: .5;
  max-width: 200px;
  margin: 0 auto;
}

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

.feature-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all .3s;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-warm);
}

.feature-icon {
  width: 68px; height: 68px;
  background: var(--primary-light);
  border-radius: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 1.8rem;
  color: var(--primary);
}

.feature-card h4 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: .92rem;
  color: var(--gray-500);
  line-height: 1.65;
}

/* ===== ABOUT PREVIEW ===== */
.about-preview { background: var(--warm-bg2); }

.about-preview-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.about-tag {
  display: inline-block;
  background: rgba(255,255,255,.7);
  backdrop-filter: blur(8px);
  color: var(--primary-dark);
  padding: 8px 20px;
  border-radius: 100px;
  font-size: .92rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.about-text h2 {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 16px;
  line-height: 1.3;
}

.about-text p {
  color: var(--gray-500);
  margin-bottom: 24px;
  line-height: 1.8;
}

.about-highlights {
  margin-bottom: 32px;
}

.about-highlights li {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 0;
  font-size: .95rem;
  color: var(--gray-700);
}

.about-highlights li i {
  color: var(--amc8-color);
  font-size: 1rem;
}

/* Teacher Card */
.teacher-card {
  background: linear-gradient(135deg, #f97316 0%, #ea580c 100%);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  color: var(--white);
  text-align: center;
  box-shadow: 0 16px 48px rgba(249,115,22,.2);
}

.teacher-avatar {
  width: 100px; height: 100px;
  background: rgba(255,255,255,.2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  border: 3px solid rgba(255,255,255,.4);
}

.avatar-icon {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--white);
}

.teacher-info h3 {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 4px;
}

.teacher-info p {
  font-size: .9rem;
  opacity: .8;
  margin-bottom: 16px;
}

.teacher-tags {
  display: flex;
  gap: 8px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.teacher-tags span {
  background: rgba(255,255,255,.2);
  border: 1px solid rgba(255,255,255,.3);
  padding: 4px 12px;
  border-radius: 100px;
  font-size: .78rem;
  font-weight: 500;
}

.teacher-org {
  font-size: .85rem;
  opacity: .75;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

/* ===== FOOTER ===== */
.footer {
  background: #1e293b;
  color: rgba(255,255,255,.75);
  padding: 64px 0 0;
}

.footer-main {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1.5fr 1.5fr;
  gap: 32px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255,255,255,.1);
}

.footer-brand .logo {
  margin-bottom: 16px;
}

.footer-brand p {
  font-size: .9rem;
  opacity: .6;
  line-height: 1.7;
}

.footer-links h4,
.footer-contact h4 {
  font-size: .95rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 16px;
}

.footer-links ul li {
  padding: 4px 0;
}

.footer-links ul li a {
  font-size: .88rem;
  opacity: .6;
  transition: opacity .2s;
}

.footer-links ul li a:hover {
  opacity: 1;
}

.footer-contact p {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: .88rem;
  opacity: .6;
  padding: 4px 0;
}

.footer-contact p i {
  width: 16px;
  opacity: .8;
}

.footer-bottom {
  padding: 20px 0;
  text-align: center;
}

.footer-bottom p {
  font-size: .82rem;
  opacity: .4;
}

/* ===== AMC8 / AMC10 PAGE ===== */
.page-hero {
  padding-top: 120px;
  padding-bottom: 64px;
  background: linear-gradient(135deg, #fff7ed 0%, #fff1eb 100%);
  text-align: center;
}

.page-hero.amc8 { background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%); }
.page-hero.amc10 { background: linear-gradient(135deg, #fff7ed 0%, #ffedd5 100%); }
.page-hero.videos-hero { background: linear-gradient(135deg, #fffbeb 0%, #fef3c7 100%); }
.page-hero.about-hero { background: linear-gradient(135deg, #f97316 0%, #ea580c 100%); color: #fff; }

.page-hero h1 {
  font-size: 2.8rem;
  font-weight: 800;
  margin-bottom: 16px;
}

.page-hero p {
  font-size: 1.1rem;
  color: var(--gray-500);
  max-width: 600px;
  margin: 0 auto 32px;
}

/* Topic Grid */
.topics-section { padding: 80px 0; }

.topic-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.topic-card {
  background: var(--white);
  border-radius: var(--radius);
  border: 1px solid var(--gray-300);
  overflow: hidden;
  transition: all .3s;
  cursor: pointer;
}

.topic-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary);
}

.topic-header {
  padding: 24px 24px 16px;
  display: flex;
  align-items: center;
  gap: 14px;
}

.topic-emoji { font-size: 1.8rem; }

.topic-header h3 {
  font-size: 1.05rem;
  font-weight: 700;
}

.topic-header .topic-level {
  font-size: .75rem;
  background: var(--primary-light);
  color: var(--primary);
  padding: 2px 10px;
  border-radius: 100px;
  margin-left: auto;
}

.topic-body {
  padding: 0 24px 24px;
}

.topic-body p {
  font-size: .88rem;
  color: var(--gray-500);
  line-height: 1.65;
  margin-bottom: 16px;
}

.topic-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.topic-tags span {
  background: var(--gray-100);
  color: var(--gray-700);
  font-size: .75rem;
  padding: 3px 10px;
  border-radius: 6px;
}

/* Video Cards */
.video-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.video-card {
  background: var(--white);
  border-radius: var(--radius);
  border: 1px solid var(--gray-300);
  overflow: hidden;
  transition: all .3s;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.video-thumb {
  background: var(--primary);
  height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.video-play {
  width: 60px; height: 60px;
  background: rgba(255,255,255,.25);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  transition: all .3s;
}

.video-card:hover .video-play {
  background: rgba(255,255,255,.4);
  transform: scale(1.1);
}

.video-info {
  padding: 20px;
}

.video-info h4 {
  font-size: .98rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.video-info p {
  font-size: .85rem;
  color: var(--gray-500);
}

.video-meta {
  display: flex;
  gap: 12px;
  margin-top: 12px;
}

.video-tag {
  font-size: .75rem;
  background: var(--primary-light);
  color: var(--primary);
  padding: 2px 10px;
  border-radius: 100px;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .topic-grid { grid-template-columns: repeat(2, 1fr); }
  .video-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav { display: none; }
  .nav.open { display: block; position: absolute; top: 68px; left: 0; right: 0; background: var(--white); border-bottom: 1px solid var(--gray-300); padding: 16px; }
  .nav.open ul { flex-direction: column; }
  .hamburger { display: flex; }

  .hero .container { grid-template-columns: 1fr; gap: 40px; }
  .hero-title { font-size: 2rem; }
  .hero-visual { display: none; }
  .hero-stats { gap: 24px; }

  .comp-cards { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .about-preview-inner { grid-template-columns: 1fr; }
  .footer-main { grid-template-columns: 1fr; gap: 32px; }
  .path-steps { flex-direction: column; }
  .path-arrow { transform: rotate(90deg); }
  .topic-grid { grid-template-columns: 1fr; }
  .video-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .section { padding: 60px 0; }
  .feature-grid { grid-template-columns: 1fr; }
  .hero-btns { flex-direction: column; }
}

/* ===== NAV DROPDOWN ===== */
.nav-dropdown { position: relative; }
.nav-dropdown > a { cursor: pointer; }

.dropdown-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--white);
  border: 1px solid rgba(0,0,0,.08);
  border-radius: 14px;
  box-shadow: 0 12px 40px rgba(0,0,0,.1);
  min-width: 200px;
  padding: 8px 0;
  z-index: 1001;
  margin-top: 8px;
  animation: dropIn .2s ease-out;
}

@keyframes dropIn {
  from { opacity: 0; transform: translateX(-50%) translateY(-6px); }
  to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* 顶部小三角指示器 */
.dropdown-menu::before {
  content: "";
  position: absolute;
  top: -6px;
  left: 50%;
  transform: translateX(-50%) rotate(45deg);
  width: 12px;
  height: 12px;
  background: #ffffff;
  border-left: 1px solid rgba(0,0,0,.08);
  border-top: 1px solid rgba(0,0,0,.08);
}

.nav-dropdown:hover .dropdown-menu,
.nav-dropdown.open .dropdown-menu { display: block; }

.dropdown-menu a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  font-size: .92rem;
  color: var(--gray-700);
  transition: all .15s;
  white-space: nowrap;
  border-radius: 8px;
  margin: 2px 6px;
}

.dropdown-menu a:hover {
  background: var(--primary-light);
  color: var(--primary-dark);
  padding-left: 22px;
}

/* ===== SECTION BADGE ===== */
.section-badge {
  display: inline-block;
  padding: 6px 18px;
  border-radius: 100px;
  font-size: .85rem;
  font-weight: 600;
  margin-bottom: 12px;
}

/* ===== MODULES GRID (五大模块) ===== */
.modules-section { background: var(--warm-bg); }

.modules-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
  margin-top: 16px;
}

.module-card {
  position: relative;
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px 20px 28px;
  text-align: center;
  border: 1px solid var(--gray-300);
  transition: all .3s;
  overflow: hidden;
  display: block;
}

.module-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-warm);
  border-color: var(--primary);
}

.module-num {
  position: absolute;
  top: 12px;
  left: 16px;
  font-size: .75rem;
  font-weight: 700;
  color: var(--gray-300);
}

.module-icon-wrap {
  width: 68px;
  height: 68px;
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 2rem;
  transition: transform .3s;
}

.module-card:hover .module-icon-wrap {
  transform: scale(1.1) rotate(-5deg);
}

.module-knowledge .module-icon-wrap { background: #d1fae5; }
.module-video .module-icon-wrap { background: #fef3c7; }
.module-papers .module-icon-wrap { background: #ffe4e6; }
.module-training .module-icon-wrap { background: #ede9fe; }
.module-exam .module-icon-wrap { background: #fce7f3; }

.module-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 4px;
}

.module-subtitle {
  font-size: .82rem;
  color: var(--gray-500);
  font-weight: 500;
  margin-bottom: 12px;
  font-style: italic;
}

.module-desc {
  font-size: .88rem;
  color: var(--gray-500);
  line-height: 1.6;
  margin-bottom: 14px;
}

.module-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  justify-content: center;
  margin-bottom: 12px;
}

.module-tags span {
  font-size: .7rem;
  background: var(--gray-100);
  color: var(--gray-700);
  padding: 3px 8px;
  border-radius: 6px;
}

.module-arrow {
  color: var(--gray-300);
  transition: all .3s;
}

.module-card:hover .module-arrow {
  color: var(--primary);
  transform: translateX(4px);
}

/* ===== KNOWLEDGE SECTION ===== */
.knowledge-section { background: var(--white); }

.knowledge-intro { margin-bottom: 64px; }

.ki-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--gray-300);
}

.ki-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.ki-preview {
  padding: 24px;
  border-right: 1px solid var(--gray-300);
  display: flex;
  gap: 16px;
}

.ki-sidebar {
  width: 120px;
  flex-shrink: 0;
  background: var(--gray-100);
  border-radius: var(--radius);
  padding: 16px 12px;
}

.ki-sidebar-title {
  font-size: .75rem;
  font-weight: 700;
  color: var(--gray-500);
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.ki-item {
  font-size: .8rem;
  color: var(--gray-500);
  padding: 6px 8px;
  border-radius: 6px;
  margin-bottom: 4px;
  cursor: default;
  transition: all .15s;
}

.ki-item.active {
  background: var(--primary);
  color: var(--white);
  font-weight: 600;
}

.ki-content-preview { flex: 1; }

.ki-title {
  font-size: .95rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 2px;
}

.ki-subtitle {
  font-size: .78rem;
  color: var(--primary);
  font-weight: 500;
  margin-bottom: 10px;
}

.ki-line {
  height: 2px;
  background: var(--gray-100);
  border-radius: 1px;
  margin-bottom: 12px;
}

.ki-text {
  height: 10px;
  background: var(--gray-100);
  border-radius: 4px;
  margin-bottom: 8px;
}

.ki-text.short { width: 60%; }

.ki-box {
  margin-top: 14px;
  padding: 10px 12px;
  border-radius: 8px;
  border-left: 3px solid;
}

.ki-box.example { border-color: #f59e0b; background: #fffbeb; }
.ki-box.practice { border-color: #059669; background: #f0fdf4; }

.ki-box-label {
  font-size: .72rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.ki-box.example .ki-box-label { color: #d97706; }
.ki-box.practice .ki-box-label { color: #059669; }

.ki-box-text {
  height: 8px;
  background: rgba(0,0,0,.06);
  border-radius: 3px;
}

.ki-desc {
  padding: 32px;
}

.ki-desc h4 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 20px;
}

.ki-desc ul { list-style: none; }

.ki-desc li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 8px 0;
  font-size: .9rem;
  color: var(--gray-700);
  line-height: 1.6;
}

.ki-desc li i {
  color: var(--amc8-color);
  margin-top: 3px;
  flex-shrink: 0;
}

/* Knowledge Courses */
.knowledge-courses {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.kc-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-300);
  transition: all .3s;
}

.kc-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.kc-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--gray-300);
}

.kc-badge {
  display: inline-block;
  font-size: .7rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 6px;
  margin-bottom: 8px;
}

.amc8-branch .kc-badge { background: #d1fae5; color: var(--amc8-color); }
.amc10-branch .kc-badge { background: #ffedd5; color: var(--amc10-color); }
.amc12-branch .kc-badge { background: #ede9fe; color: var(--amc12-color); }

.kc-header h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--dark);
}

.kc-header p {
  font-size: .85rem;
  color: var(--gray-500);
}

.kc-topics { padding: 8px 12px; }

.kc-topic {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px;
  border-radius: 12px;
  transition: all .2s;
}

.kc-topic:hover { background: var(--warm-bg2); transform: translateX(4px); }

.kc-emoji { font-size: 1.4rem; flex-shrink: 0; }

.kc-topic strong {
  display: block;
  font-size: .92rem;
  color: var(--dark);
}

.kc-topic small {
  display: block;
  font-size: .78rem;
  color: var(--gray-500);
  margin-top: 2px;
}

.kc-status {
  font-size: .7rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 6px;
  background: #fef3c7;
  color: #d97706;
  margin-left: auto;
  flex-shrink: 0;
}

.kc-topic.active-topic {
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
}

/* ===== VIDEO SECTION ===== */
.video-section { background: var(--warm-bg2); }

.video-showcase {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 12px;
}

.vs-feature {
  background: var(--gray-100);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  transition: all .3s;
}

.vs-feature:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.vs-icon {
  font-size: 2.5rem;
  color: #d97706;
  margin-bottom: 16px;
}

.vs-feature h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.vs-feature p {
  font-size: .85rem;
  color: var(--gray-500);
  line-height: 1.6;
}

/* ===== PAPERS SECTION ===== */
.papers-section { background: var(--white); }

.papers-visual {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 40px;
  text-align: center;
}

.pv-tabs {
  display: flex;
  gap: 4px;
  justify-content: center;
  margin-bottom: 24px;
}

.pv-tab {
  padding: 10px 24px;
  border: 2px solid var(--gray-300);
  border-radius: 10px;
  background: var(--white);
  font-size: .9rem;
  font-weight: 600;
  color: var(--gray-500);
  cursor: pointer;
  transition: all .2s;
}

.pv-tab:hover { border-color: var(--primary); color: var(--primary); }

.pv-tab.active {
  background: var(--primary);
  color: var(--white);
  border-color: transparent;
}

.pv-years {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.pv-year {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 72px;
  height: 48px;
  background: var(--gray-100);
  border: 1px solid var(--gray-300);
  border-radius: 10px;
  font-size: .9rem;
  font-weight: 600;
  color: var(--gray-700);
  cursor: pointer;
  transition: all .2s;
}

.pv-year:not(.coming):hover {
  background: var(--primary-light);
  border-color: var(--primary);
  color: var(--primary);
}

.pv-year.coming {
  opacity: .5;
  cursor: not-allowed;
  color: var(--gray-500);
  background: var(--white);
}

.papers-features {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.pf-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  background: var(--white);
  padding: 24px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all .3s;
}

.pf-item:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }

.pf-icon {
  width: 44px;
  height: 44px;
  background: #ffe4e6;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  color: #e11d48;
  flex-shrink: 0;
}

.pf-item strong {
  display: block;
  font-size: .92rem;
  margin-bottom: 4px;
}

.pf-item p {
  font-size: .8rem;
  color: var(--gray-500);
  line-height: 1.5;
}

/* ===== TRAINING SECTION ===== */
.training-section { background: var(--warm-bg); }

.training-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 48px;
}

.train-card {
  background: var(--white);
  border: 2px solid var(--gray-300);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  text-align: center;
  transition: all .3s;
  position: relative;
}

.train-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: #818cf8;
}

.train-icon {
  font-size: 2.5rem;
  margin-bottom: 12px;
}

.train-card h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.train-card > p {
  font-size: .82rem;
  color: var(--gray-500);
  line-height: 1.6;
  margin-bottom: 16px;
}

.train-levels {
  display: flex;
  gap: 6px;
  justify-content: center;
  margin-bottom: 14px;
}

.tl {
  font-size: .7rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 6px;
}

.amc8-tl { background: #d1fae5; color: var(--amc8-color); }
.amc10-tl { background: #dbeafe; color: var(--amc10-color); }
.amc12-tl { background: #ede9fe; color: var(--amc12-color); }

.train-status {
  font-size: .78rem;
  color: var(--gray-500);
  font-style: italic;
}

/* Daily Problem */
.daily-problem {
  background: linear-gradient(135deg, #f97316 0%, #ea580c 100%);
  border-radius: var(--radius-lg);
  padding: 36px 40px;
  color: var(--white);
  max-width: 640px;
  margin: 0 auto;
}

.dp-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
}

.dp-badge {
  background: rgba(255,255,255,.2);
  border: 1px solid rgba(255,255,255,.3);
  padding: 4px 14px;
  border-radius: 100px;
  font-size: .8rem;
  font-weight: 600;
}

.dp-source {
  font-size: .82rem;
  opacity: .7;
}

.dp-question {
  font-size: 1.05rem;
  line-height: 1.7;
  margin-bottom: 20px;
}

.dp-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.dp-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 18px;
  background: rgba(255,255,255,.12);
  border: 1px solid rgba(255,255,255,.2);
  border-radius: 10px;
  cursor: pointer;
  transition: all .2s;
  font-size: .92rem;
}

.dp-option:hover {
  background: rgba(255,255,255,.22);
}

.dp-option.correct {
  background: rgba(34,197,94,.3);
  border-color: #22c55e;
}

.dp-option.wrong {
  background: rgba(239,68,68,.3);
  border-color: #ef4444;
}

.dp-option.disabled { pointer-events: none; opacity: .7; }

.dp-feedback {
  margin-top: 16px;
  padding: 14px 18px;
  border-radius: 10px;
  font-size: .9rem;
  line-height: 1.6;
}

.dp-feedback.correct-fb { background: rgba(34,197,94,.2); }
.dp-feedback.wrong-fb { background: rgba(239,68,68,.2); }

/* ===== EXAM SECTION ===== */
.exam-section { background: var(--warm-bg2); }

.exam-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}

.exam-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  text-align: center;
  border: 2px solid var(--gray-300);
  transition: all .3s;
}

.exam-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-warm);
}

.exam-card.featured-exam {
  border-color: var(--primary);
  box-shadow: var(--shadow-warm);
}

.exam-level {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 14px;
}

.featured-exam .exam-level { color: var(--primary); }

.exam-meta {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 16px;
}

.exam-meta span {
  font-size: .82rem;
  color: var(--gray-500);
  display: flex;
  align-items: center;
  gap: 4px;
}

.exam-desc {
  font-size: .88rem;
  color: var(--gray-500);
  margin-bottom: 24px;
  line-height: 1.6;
}

.exam-features {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.ef-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  background: var(--white);
  padding: 24px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all .3s;
}

.ef-item:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }

.ef-item > i {
  font-size: 1.3rem;
  color: #db2777;
  flex-shrink: 0;
  margin-top: 2px;
}

.ef-item strong {
  display: block;
  font-size: .92rem;
  margin-bottom: 4px;
}

.ef-item p {
  font-size: .8rem;
  color: var(--gray-500);
  line-height: 1.5;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .modules-grid { grid-template-columns: repeat(3, 1fr); }
  .training-grid { grid-template-columns: repeat(2, 1fr); }
  .papers-features,
  .exam-features { grid-template-columns: repeat(2, 1fr); }
  .ki-layout { grid-template-columns: 1fr; }
  .ki-preview { border-right: none; border-bottom: 1px solid var(--gray-300); }
  .knowledge-courses { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .modules-grid { grid-template-columns: 1fr 1fr; }
  .video-showcase { grid-template-columns: 1fr; }
  .exam-cards { grid-template-columns: 1fr; }
  .training-grid { grid-template-columns: 1fr; }
  .papers-features,
  .exam-features { grid-template-columns: 1fr; }
  .hero-visual { display: none; }
  .nav-dropdown .dropdown-menu { display: none !important; }
  .pf-item, .ef-item { flex-direction: column; align-items: center; text-align: center; }
}

@media (max-width: 480px) {
  .modules-grid { grid-template-columns: 1fr; }
  .daily-problem { padding: 24px 20px; }
}