:root {
  --ink: #203431;
  --muted: #66736f;
  --line: #e2e7e2;
  --paper: #fffdf7;
  --white: #ffffff;
  --cream: #f7efe3;
  --sage: #d9e6d8;
  --clay: #eed8cc;
  --coral: #d85f45;
  --teal: #2f6f68;
  --gold: #d69a43;
  --chinese: #f3c3c7;
  --english: #f7cfa9;
  --math: #c9e6ce;
  --society: #c7dfec;
  --science: #d8cbe9;
  --shadow: 0 24px 60px rgba(32, 52, 49, 0.13);
  font-family: "Noto Sans TC", "Microsoft JhengHei", system-ui, sans-serif;
  color: var(--ink);
  background: var(--paper);
  scroll-behavior: smooth;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background:
    linear-gradient(90deg, rgba(216, 95, 69, 0.1) 0 18%, transparent 18% 100%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(255, 253, 247, 0.94)),
    repeating-linear-gradient(0deg, rgba(32, 52, 49, 0.035) 0 1px, transparent 1px 44px),
    var(--paper);
}

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

a {
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 12px clamp(18px, 4vw, 54px);
  border-bottom: 1px solid rgba(32, 52, 49, 0.1);
  background: rgba(255, 253, 247, 0.9);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: max-content;
  text-decoration: none;
  font-weight: 800;
  letter-spacing: 0;
}

.brand img {
  width: 34px;
  height: 34px;
  object-fit: contain;
}

.top-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(10px, 2vw, 28px);
  font-size: 0.95rem;
  color: var(--muted);
}

.top-nav a {
  padding: 8px 0;
  border-bottom: 2px solid transparent;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.top-nav a:hover,
.top-nav a:focus-visible {
  border-color: var(--ink);
  color: var(--ink);
}

.hero {
  position: relative;
  display: flex;
  align-items: center;
  min-height: calc(100svh - 72px);
  padding: clamp(46px, 8vw, 96px) clamp(20px, 6vw, 76px) 44px;
  overflow: hidden;
}

.hero-copy {
  position: relative;
  z-index: 1;
  max-width: 860px;
}

.eyebrow {
  margin: 0 0 12px;
  color: #6a7f7c;
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1,
h2,
p {
  letter-spacing: 0;
}

h1 {
  margin: 0;
  max-width: min(100%, 1120px);
  font-size: clamp(2.1rem, 5.2vw, 4.8rem);
  line-height: 1.08;
  font-weight: 900;
}

h2 {
  margin: 0;
  font-size: clamp(1.85rem, 4vw, 3.15rem);
  line-height: 1.18;
}

.lead,
.section p,
.download-copy p {
  color: var(--muted);
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  line-height: 1.9;
}

.lead {
  max-width: 640px;
  margin: 24px 0 0;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.primary-button,
.secondary-button,
.text-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 20px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 800;
}

.primary-button {
  background: linear-gradient(135deg, var(--teal), var(--ink));
  color: var(--white);
  box-shadow: 0 12px 28px rgba(39, 50, 56, 0.18);
}

.secondary-button {
  border: 1px solid var(--line);
  background: var(--white);
  color: var(--ink);
}

.text-link {
  min-height: 42px;
  margin-top: 18px;
  border: 1px solid var(--line);
  background: var(--white);
  color: var(--ink);
}

.subject-strip {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
  padding: 0 clamp(20px, 6vw, 76px) 52px;
}

.subject-pill {
  display: grid;
  min-height: 74px;
  place-items: center;
  border: 1px solid rgba(39, 50, 56, 0.06);
  border-radius: 8px;
  box-shadow: 0 10px 24px rgba(37, 50, 56, 0.06);
  text-decoration: none;
  font-weight: 900;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.subject-pill:hover,
.subject-pill:focus-visible {
  transform: translateY(-3px);
  box-shadow: 0 16px 34px rgba(37, 50, 56, 0.12);
}

.chinese {
  --subject: var(--chinese);
}

.english {
  --subject: var(--english);
}

.math {
  --subject: var(--math);
}

.society {
  --subject: var(--society);
}

.science {
  --subject: var(--science);
}

.subject-pill,
.filter-button,
.student-card {
  background: var(--subject, var(--white));
}

.section {
  padding: clamp(64px, 8vw, 112px) clamp(20px, 6vw, 76px);
  scroll-margin-top: 84px;
}

.soft-band {
  background:
    linear-gradient(90deg, rgba(202, 228, 241, 0.3), rgba(221, 208, 239, 0.24)),
    #fbfdfc;
}

.section-heading {
  max-width: 760px;
  margin-bottom: 30px;
}

.feature-layout {
  display: grid;
  grid-template-columns: minmax(260px, 0.72fr) minmax(320px, 1fr);
  gap: clamp(24px, 5vw, 64px);
  align-items: center;
  padding: clamp(16px, 2vw, 24px);
  border: 1px solid rgba(37, 50, 56, 0.08);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.64);
}

.feature-layout.reverse {
  grid-template-columns: minmax(320px, 1fr) minmax(260px, 0.72fr);
}

.pdf-frame {
  width: 100%;
  height: min(72vh, 720px);
  min-height: 430px;
  border: 1px solid rgba(37, 50, 56, 0.1);
  border-radius: 8px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.pdf-frame.compact {
  height: 560px;
  min-height: 420px;
}

.guide-points {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.guide-points span {
  padding: 9px 14px;
  border-radius: 999px;
  background: var(--white);
  border: 1px solid var(--line);
  color: var(--ink);
  font-weight: 800;
}

.analysis-section {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.72), rgba(255, 254, 250, 0.96)),
    linear-gradient(90deg, rgba(247, 201, 206, 0.22), rgba(255, 216, 184, 0.18), rgba(207, 233, 207, 0.2), rgba(202, 228, 241, 0.22), rgba(221, 208, 239, 0.18));
}

.learning-support-section {
  background:
    linear-gradient(135deg, rgba(216, 95, 69, 0.14), rgba(214, 154, 67, 0.13), rgba(47, 111, 104, 0.12), rgba(216, 203, 233, 0.16)),
    rgba(255, 253, 247, 0.96);
}

.learning-overview {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.learning-overview article {
  padding: 22px;
  border: 1px solid rgba(32, 52, 49, 0.09);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.82);
  box-shadow: 0 16px 36px rgba(32, 52, 49, 0.08);
}

.learning-overview span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  margin-bottom: 14px;
  border-radius: 999px;
  background: var(--ink);
  color: var(--white);
  font-weight: 900;
}

.learning-overview h3 {
  margin: 0 0 10px;
  font-size: 1.2rem;
}

.learning-overview p {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.75;
}

.analysis-summary {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-bottom: 22px;
}

.analysis-card,
.analysis-subject,
.analysis-note {
  border: 1px solid rgba(37, 50, 56, 0.08);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  box-shadow: 0 14px 34px rgba(37, 50, 56, 0.07);
}

.analysis-card {
  padding: clamp(18px, 2.4vw, 28px);
}

.analysis-card h3,
.analysis-subject h3 {
  margin: 0 0 12px;
  font-size: 1.25rem;
}

.analysis-card ul {
  display: grid;
  gap: 10px;
  margin: 0;
  padding-left: 1.1rem;
  color: var(--muted);
  line-height: 1.75;
}

.analysis-card.strength {
  border-top: 6px solid var(--math);
}

.analysis-card.improve {
  border-top: 6px solid var(--english);
}

.analysis-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}

.analysis-subject {
  padding: 18px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.7), rgba(255, 255, 255, 0.86)),
    var(--subject, var(--white));
}

.analysis-subject p {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.75;
}

.analysis-note {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
  padding: 18px;
  color: var(--ink);
}

.analysis-note span {
  color: var(--muted);
}

.ai-section {
  background:
    linear-gradient(180deg, rgba(255, 254, 250, 0.92), rgba(248, 244, 234, 0.76)),
    var(--paper);
}

.ogsm-flow {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
  margin-bottom: 24px;
  border: 1px solid rgba(37, 50, 56, 0.12);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 16px 38px rgba(37, 50, 56, 0.08);
}

.ogsm-step {
  position: relative;
  min-height: 210px;
  padding: 24px 22px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.82), rgba(255, 216, 184, 0.28)),
    var(--white);
}

.ogsm-step + .ogsm-step {
  border-left: 1px solid rgba(37, 50, 56, 0.1);
}

.ogsm-step:not(:last-child)::after {
  position: absolute;
  top: 50%;
  right: -10px;
  z-index: 2;
  width: 20px;
  height: 20px;
  border-top: 1px solid rgba(37, 50, 56, 0.16);
  border-right: 1px solid rgba(37, 50, 56, 0.16);
  background: #fff3e7;
  content: "";
  transform: translateY(-50%) rotate(45deg);
}

.ogsm-step span {
  display: inline-flex;
  margin-bottom: 10px;
  color: #a15e2f;
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.ogsm-step strong {
  display: block;
  margin-bottom: 10px;
  font-size: 1.35rem;
}

.ogsm-step p,
.support-grid p,
.ai-helper p {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-bottom: 24px;
}

.support-grid article {
  min-height: 190px;
  padding: 22px;
  border: 1px solid rgba(37, 50, 56, 0.08);
  border-radius: 8px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.78), rgba(247, 207, 169, 0.42)),
    var(--white);
  box-shadow: 0 14px 32px rgba(37, 50, 56, 0.08);
}

.support-grid h3 {
  margin: 0 0 12px;
  font-size: 1.18rem;
}

.school-resource-panel {
  display: grid;
  grid-template-columns: minmax(280px, 0.58fr) minmax(320px, 1fr);
  gap: clamp(18px, 3vw, 32px);
  align-items: center;
  margin-bottom: 24px;
  padding: clamp(18px, 3vw, 28px);
  border: 1px solid rgba(32, 52, 49, 0.1);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  box-shadow: 0 18px 42px rgba(32, 52, 49, 0.09);
}

.school-resource-panel img {
  width: 100%;
  border: 1px solid rgba(32, 52, 49, 0.08);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.school-resource-panel h3 {
  margin: 0 0 12px;
  font-size: 1.55rem;
}

.ai-helper {
  display: grid;
  grid-template-columns: minmax(240px, 0.7fr) minmax(260px, 0.9fr);
  gap: 18px;
  align-items: start;
  padding: clamp(18px, 3vw, 28px);
  border: 1px solid rgba(37, 50, 56, 0.1);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(201, 230, 206, 0.34), rgba(199, 223, 236, 0.28), rgba(216, 203, 233, 0.24)),
    rgba(255, 255, 255, 0.86);
  box-shadow: 0 18px 42px rgba(37, 50, 56, 0.09);
}

.ai-helper h3 {
  margin: 0 0 10px;
  font-size: 1.55rem;
}

.ai-actions {
  display: grid;
  gap: 10px;
}

.ai-actions button {
  min-height: 46px;
  padding: 0 16px;
  border: 1px solid rgba(37, 50, 56, 0.12);
  border-radius: 999px;
  background: var(--white);
  color: var(--ink);
  cursor: pointer;
  font: inherit;
  font-weight: 900;
  text-align: left;
}

.ai-actions button:hover,
.ai-actions button:focus-visible,
.ai-actions button.active {
  background: var(--ink);
  color: var(--white);
}

.ai-response {
  grid-column: 1 / -1;
  padding: 18px;
  border: 1px solid rgba(37, 50, 56, 0.08);
  border-radius: 8px;
  background: var(--white);
  color: var(--muted);
  line-height: 1.8;
}

.aisi-section {
  background:
    linear-gradient(135deg, rgba(255, 216, 184, 0.28), rgba(207, 233, 207, 0.2), rgba(202, 228, 241, 0.24)),
    #fffefa;
}

.aisi-title {
  max-width: 100%;
  white-space: nowrap;
}

.aisi-hero {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 22px;
  padding: clamp(18px, 3vw, 30px);
  border: 1px solid rgba(37, 50, 56, 0.1);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.82);
  box-shadow: 0 16px 38px rgba(37, 50, 56, 0.08);
}

.aisi-hero h3,
.aisi-resource h3 {
  margin: 0 0 10px;
  font-size: 1.35rem;
}

.aisi-platform-title {
  color: #c0392b;
}

.aisi-login-button {
  min-height: 56px;
  padding: 0 28px;
  background: #c0392b;
  box-shadow: 0 16px 34px rgba(192, 57, 43, 0.28);
  font-size: 1.08rem;
  white-space: nowrap;
}

.aisi-login-button:hover,
.aisi-login-button:focus-visible {
  background: #9f2f24;
}

.aisi-hero p,
.aisi-resource p {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}

.aisi-resources {
  display: grid;
  gap: 18px;
}

.aisi-resource {
  display: grid;
  grid-template-columns: minmax(240px, 0.62fr) minmax(320px, 1fr);
  gap: clamp(18px, 3vw, 28px);
  align-items: center;
  padding: clamp(16px, 2vw, 24px);
  border: 1px solid rgba(37, 50, 56, 0.08);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.74);
  box-shadow: 0 14px 34px rgba(37, 50, 56, 0.07);
}

.resource-copy {
  max-width: 520px;
}

.aisi-video {
  width: 100%;
  min-height: 320px;
  max-height: 560px;
  border: 1px solid rgba(37, 50, 56, 0.1);
  border-radius: 8px;
  background: var(--ink);
  box-shadow: var(--shadow);
}

.sample-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 26px;
}

.filter-button {
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid rgba(39, 50, 56, 0.08);
  border-radius: 999px;
  color: var(--ink);
  cursor: pointer;
  font: inherit;
  font-weight: 900;
}

.filter-button.active {
  background: var(--ink);
  color: var(--white);
}

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

.empty-state {
  grid-column: 1 / -1;
  margin: 0;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  color: var(--muted);
}

.student-card {
  overflow: hidden;
  border: 1px solid rgba(39, 50, 56, 0.08);
  border-radius: 8px;
  box-shadow: 0 14px 32px rgba(39, 50, 56, 0.08);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.student-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 42px rgba(39, 50, 56, 0.12);
}

.sample-preview {
  height: 360px;
  background: var(--white);
  border: 0;
  border-bottom: 1px solid rgba(39, 50, 56, 0.08);
}

.sample-preview iframe {
  width: 100%;
  height: 100%;
  border: 0;
  background: var(--white);
}

.student-meta {
  display: grid;
  gap: 8px;
  padding: 16px;
}

.student-meta h3 {
  margin: 0;
  font-size: 1.1rem;
  line-height: 1.35;
}

.student-meta p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.student-meta a {
  width: max-content;
  color: var(--ink);
  font-weight: 900;
  text-decoration: none;
  border-bottom: 2px solid rgba(39, 50, 56, 0.22);
}

.download-section {
  display: grid;
  grid-template-columns: minmax(260px, 0.75fr) minmax(320px, 1fr);
  gap: clamp(24px, 5vw, 64px);
  align-items: center;
  background:
    linear-gradient(135deg, rgba(247, 201, 206, 0.32), rgba(255, 216, 184, 0.24), rgba(202, 228, 241, 0.28), rgba(221, 208, 239, 0.24)),
    var(--cream);
}

.download-copy {
  max-width: 620px;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: 28px 20px;
  border-top: 1px solid var(--line);
  background: var(--white);
  color: var(--muted);
  font-weight: 800;
}

.site-footer img {
  width: 96px;
  max-height: 44px;
  object-fit: contain;
}

.site-footer p {
  margin: 0;
}

@media (max-width: 880px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
  }

  .top-nav {
    width: 100%;
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .hero,
  .feature-layout,
  .feature-layout.reverse,
  .analysis-summary,
  .learning-overview,
  .ogsm-flow,
  .support-grid,
  .ai-helper,
  .school-resource-panel,
  .aisi-resource,
  .download-section {
    grid-template-columns: 1fr;
  }

  .aisi-hero {
    align-items: flex-start;
    flex-direction: column;
  }

  .ogsm-step + .ogsm-step {
    border-top: 1px solid rgba(37, 50, 56, 0.1);
    border-left: 0;
  }

  .ogsm-step:not(:last-child)::after {
    display: none;
  }

  .hero {
    min-height: auto;
  }

  .subject-strip {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .subject-pill:last-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 560px) {
  .brand img {
    width: 34px;
    height: 34px;
  }

  .hero-actions,
  .primary-button,
  .secondary-button,
  .text-link {
    width: 100%;
  }

  .subject-strip {
    grid-template-columns: 1fr;
  }

  .subject-pill:last-child {
    grid-column: auto;
  }

  .pdf-frame,
  .pdf-frame.compact {
    min-height: 360px;
    height: 62vh;
  }

  .sample-preview {
    height: 310px;
  }

  .site-footer {
    flex-direction: column;
  }

  h1 {
    font-size: clamp(2rem, 13vw, 3.25rem);
  }

  .aisi-title {
    white-space: normal;
  }
}