:root {
  --ikb: #002fa7;
  --ikb-hover: #001f80;
  --ikb-soft: rgba(0, 47, 167, 0.08);
  --ink: #111827;
  --ink-2: #374151;
  --gray-1: #fafafa;
  --gray-2: #f3f4f6;
  --gray-3: #e5e7eb;
  --gray-5: #6b7280;
  --gray-6: #9ca3af;
  --warm: #f8f1e7;
  --sage: #eaf3ef;
  --amber: #b7791f;
  --radius-card: 16px;
  --shadow-card: 0 18px 44px rgba(17, 24, 39, 0.09);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: #fff;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

.card-link {
  display: block;
  height: 100%;
}

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

button,
input {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--gray-3);
}

.nav {
  width: min(1200px, calc(100% - 48px));
  height: 64px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0;
  white-space: nowrap;
}

.brand-mark {
  width: 28px;
  height: 28px;
  color: var(--ikb);
  flex: 0 0 auto;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav-links a {
  font-size: 14px;
  color: var(--ink-2);
  transition: color 0.2s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--ikb);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 40px;
  padding: 0 18px;
  border-radius: 8px;
  background: var(--ikb);
  color: #fff;
  border: 0;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  transition: transform 0.25s ease, background 0.25s ease;
}

.nav-cta:hover {
  background: var(--ikb-hover);
  transform: translateY(-1px);
}

.wrap {
  width: min(1200px, calc(100% - 48px));
  margin: 0 auto;
}

.wide {
  width: min(1280px, calc(100% - 48px));
  margin: 0 auto;
}

.tutorial-home {
  background: #f7f8fb;
}

.tutorial-hero {
  padding: 84px 0 42px;
  background:
    radial-gradient(circle at 92% 10%, rgba(0, 47, 167, 0.12), transparent 26%),
    linear-gradient(180deg, #f8fafc 0%, #fff 72%, #f7f8fb 100%);
}

.hero-topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 52px;
}

.hero-pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.hero-pill {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 15px;
  border: 1px solid var(--gray-3);
  border-radius: 10px;
  background: #fff;
  color: var(--ink-2);
  font-size: 13px;
  font-weight: 650;
  white-space: nowrap;
}

.hero-pill.green,
.hero-pill.blue {
  border-color: var(--gray-3);
  background: #fff;
}

.hero-pill.peach {
  border-color: rgba(0, 47, 167, 0.18);
  background: var(--ikb-soft);
  color: var(--ikb);
}

.tutorial-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(340px, 0.58fr);
  gap: 64px;
  align-items: center;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--gray-3);
}

.tutorial-hero h1 {
  margin: 0;
  font-size: clamp(48px, 7vw, 92px);
  line-height: 1.05;
  letter-spacing: 0;
  font-weight: 820;
}

.tutorial-hero-copy {
  color: var(--gray-5);
  font-size: 17px;
  text-align: left;
  padding: 28px;
  border: 1px solid var(--gray-3);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.74);
  box-shadow: 0 18px 50px rgba(17, 24, 39, 0.05);
}

.tutorial-hero-copy p {
  margin: 0;
}

.tutorial-hero-copy p + p {
  margin-top: 12px;
}

.tutorial-board {
  padding: 52px 0 112px;
}

.board-toolbar {
  display: grid;
  grid-template-columns: 1fr minmax(260px, 360px);
  gap: 20px;
  align-items: center;
  margin-bottom: 34px;
}

.mode-switch {
  display: none;
}

.category-switch {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
}

.mode-pill {
  border: 0;
  border-radius: 999px;
  padding: 8px 14px;
  background: var(--gray-2);
  color: var(--ink-2);
  font-size: 14px;
  font-weight: 700;
}

.mode-pill.active {
  background: var(--ikb);
  color: #fff;
}

.tutorial-search {
  min-height: 46px;
  border: 1px solid var(--gray-3);
  border-radius: 12px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 18px;
  background: #fff;
  color: var(--gray-5);
  box-shadow: none;
}

.tutorial-search input {
  width: 100%;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
  font-size: 14px;
}

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

.tutorial-card {
  min-width: 0;
  border: 1px solid var(--gray-3);
  border-radius: 18px;
  background: #fff;
  padding: 0;
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.tutorial-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 18px 44px rgba(17, 24, 39, 0.08);
}

.tutorial-thumb {
  position: relative;
  aspect-ratio: 16 / 8.4;
  border-radius: 0;
  overflow: hidden;
  padding: 22px;
  display: flex;
  align-items: flex-end;
  background: linear-gradient(135deg, #111827, #002fa7);
}

.synced-thumb img,
.synced-cover img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.synced-thumb::before,
.synced-cover::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(180deg, rgba(17, 24, 39, 0.08), rgba(17, 24, 39, 0.72));
}

.tutorial-thumb::after {
  content: "";
  position: absolute;
  z-index: 2;
  inset: auto 22px 0 22px;
  height: 1px;
  background: rgba(255, 255, 255, 0.24);
}

.tutorial-thumb.t1 { background: linear-gradient(135deg, #edf2f7 0%, #cfd9e7 100%); }
.tutorial-thumb.t2 { background: linear-gradient(135deg, #1f2937 0%, #64748b 100%); }
.tutorial-thumb.t3 { background: linear-gradient(135deg, #f5f7fa 0%, #dbe6f0 100%); }
.tutorial-thumb.t4 { background: linear-gradient(135deg, #0f172a 0%, #002fa7 100%); }
.tutorial-thumb.t5 { background: linear-gradient(135deg, #083344 0%, #2563eb 100%); }
.tutorial-thumb.t6 { background: linear-gradient(135deg, #ece7df 0%, #b7a28d 100%); }
.tutorial-thumb.t7 { background: linear-gradient(135deg, #e8f2ff 0%, #bfdcff 100%); }
.tutorial-thumb.t8 { background: linear-gradient(135deg, #111827 0%, #334155 100%); }

.hot-label,
.series-label {
  position: absolute;
  z-index: 2;
  top: 18px;
  left: 18px;
  padding: 5px 9px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.86);
  color: var(--ikb);
  font-size: 12px;
  line-height: 1;
  font-weight: 800;
  letter-spacing: 0.06em;
}

.series-label {
  background: rgba(255, 255, 255, 0.86);
  color: var(--ikb);
}

.thumb-title {
  position: relative;
  z-index: 2;
  max-width: 92%;
  color: #fff;
  font-size: clamp(20px, 2vw, 26px);
  line-height: 1.16;
  font-weight: 820;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.25);
}

.tutorial-thumb.t1 .thumb-title,
.tutorial-thumb.t3 .thumb-title,
.tutorial-thumb.t6 .thumb-title,
.tutorial-thumb.t7 .thumb-title {
  color: #111827;
  text-shadow: none;
}

.tutorial-card-body {
  padding: 22px;
}

.tutorial-card-title {
  margin: 0 0 16px;
  min-height: 68px;
  font-size: 19px;
  line-height: 1.45;
  font-weight: 760;
}

.card-points {
  margin: 0 0 18px;
  padding-left: 18px;
  color: var(--gray-5);
  font-size: 14px;
  line-height: 1.65;
}

.card-points li + li {
  margin-top: 3px;
}

.source-row {
  display: none;
}

.source-logo {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: #fff;
  color: #111827;
  font-size: 23px;
  font-weight: 900;
}

.source-meta strong {
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--ink);
  font-size: 13px;
  line-height: 1.2;
}

.source-meta span {
  display: block;
  margin-top: 3px;
  color: var(--gray-5);
  font-size: 12px;
  line-height: 1.2;
}

.tool-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 0;
  align-items: center;
}

.tool-dot {
  width: auto;
  min-width: 0;
  height: auto;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 4px 10px;
  background: var(--gray-2);
  color: var(--gray-5);
  font-size: 12px;
  font-weight: 650;
}

.tool-dot.black {
  background: var(--gray-2);
  color: var(--gray-5);
}

.prompt-preview-section {
  padding: 96px 0;
  background: #111827;
  color: #fff;
}

.prompt-preview-section .section-label {
  color: #9bb7ff;
}

.prompt-preview-section .section-desc {
  color: rgba(255, 255, 255, 0.7);
}

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

.prompt-card {
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.06);
  padding: 24px;
}

.prompt-card.light {
  border-color: var(--gray-3);
  background: #fff;
  color: var(--ink);
}

.prompt-card h3 {
  margin: 14px 0 12px;
  font-size: 21px;
  line-height: 1.32;
}

.prompt-code {
  min-height: 156px;
  border-radius: 14px;
  padding: 16px;
  background: rgba(0, 0, 0, 0.22);
  color: rgba(255, 255, 255, 0.84);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px;
  line-height: 1.7;
  white-space: pre-wrap;
}

.prompt-card.light .prompt-code {
  background: #f6f7f8;
  color: var(--ink-2);
}

.copy-prompt {
  width: 100%;
  margin-top: 16px;
  min-height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 10px;
  background: #fff;
  color: var(--ikb);
  cursor: pointer;
  font-weight: 800;
}

.prompt-card.light .copy-prompt {
  border-color: var(--gray-3);
  background: var(--ikb);
  color: #fff;
}

.hero {
  min-height: 78vh;
  padding: 112px 0 72px;
  display: flex;
  align-items: flex-end;
  position: relative;
  color: #fff;
  overflow: hidden;
  background: #111827;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(4, 8, 18, 0.9) 0%, rgba(4, 8, 18, 0.62) 43%, rgba(4, 8, 18, 0.2) 100%),
    url("./ai-studio.jpg") center / cover no-repeat;
  transform: scale(1.01);
}

.hero-inner {
  position: relative;
  z-index: 1;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 28px;
  padding: 6px 13px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  color: rgba(255, 255, 255, 0.9);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.eyebrow.dark {
  color: var(--ikb);
  background: var(--ikb-soft);
  border-color: transparent;
}

.eyebrow-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
}

.hero h1,
.page-title,
.course-title {
  margin: 0;
  max-width: 960px;
  font-size: clamp(42px, 6.4vw, 76px);
  line-height: 1.08;
  letter-spacing: 0;
  font-weight: 760;
}

.hero h1 span {
  color: #b9cdfc;
}

.hero-sub {
  max-width: 680px;
  margin: 28px 0 40px;
  color: rgba(255, 255, 255, 0.78);
  font-size: clamp(16px, 1.6vw, 19px);
}

.hero-actions,
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 52px;
  padding: 0 24px;
  border-radius: 10px;
  border: 1px solid transparent;
  cursor: pointer;
  font-size: 15px;
  font-weight: 650;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease, border-color 0.25s ease;
}

.btn-primary {
  color: #fff;
  background: var(--ikb);
}

.btn-primary:hover {
  background: var(--ikb-hover);
  transform: translateY(-2px);
  box-shadow: 0 14px 30px rgba(0, 47, 167, 0.28);
}

.btn-light {
  color: var(--ikb);
  background: #fff;
}

.btn-light:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 42px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
  color: var(--ink);
  background: #fff;
  border-color: var(--gray-3);
}

.btn-secondary:hover {
  border-color: var(--ikb);
  color: var(--ikb);
  transform: translateY(-2px);
}

.btn-ghost {
  color: rgba(255, 255, 255, 0.92);
  border-color: rgba(255, 255, 255, 0.32);
  background: rgba(255, 255, 255, 0.08);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.15);
  transform: translateY(-2px);
}

.stats-strip {
  position: relative;
  z-index: 2;
  margin-top: -1px;
  background: #fff;
  border-bottom: 1px solid var(--gray-3);
}

.stats-grid {
  width: min(1200px, calc(100% - 48px));
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
}

.stat {
  padding: 34px 24px;
  border-left: 1px solid var(--gray-3);
}

.stat:last-child {
  border-right: 1px solid var(--gray-3);
}

.stat strong {
  display: block;
  font-size: clamp(26px, 3vw, 38px);
  line-height: 1.1;
  letter-spacing: 0;
}

.stat span {
  display: block;
  margin-top: 8px;
  color: var(--gray-5);
  font-size: 14px;
}

.section {
  padding: 112px 0;
}

.section.alt {
  background: var(--gray-1);
}

.section.warm {
  background: var(--warm);
}

.section-head {
  margin-bottom: 54px;
}

.section-head.center {
  text-align: center;
}

.section-head.center .section-desc,
.section-head.center .section-title {
  margin-left: auto;
  margin-right: auto;
}

.section-label {
  margin-bottom: 12px;
  color: var(--ikb);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.section-title {
  max-width: 780px;
  margin: 0 0 18px;
  font-size: clamp(31px, 4vw, 48px);
  line-height: 1.18;
  letter-spacing: 0;
  font-weight: 760;
}

.section-desc {
  max-width: 690px;
  margin: 0;
  color: var(--gray-5);
  font-size: 17px;
}

.module-grid,
.notes-grid,
.course-grid,
.works-grid,
.audience-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.module,
.note-card,
.course-card,
.work-card,
.audience-card,
.plain-card,
.review-card {
  background: #fff;
  border: 1px solid var(--gray-3);
  border-radius: var(--radius-card);
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.module:hover,
.note-card:hover,
.course-card:hover,
.work-card:hover,
.plain-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-card);
}

.module {
  padding: 34px;
}

.module-icon,
.small-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  margin-bottom: 24px;
  color: var(--ikb);
  background: var(--ikb-soft);
}

.module h3,
.course-card h3,
.audience-card h3,
.plain-card h3 {
  margin: 0 0 10px;
  font-size: 22px;
  line-height: 1.3;
}

.module p,
.course-card p,
.audience-card p,
.plain-card p {
  margin: 0;
  color: var(--gray-5);
  font-size: 15px;
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin-top: 24px;
  color: var(--ikb);
  font-size: 14px;
  font-weight: 650;
}

.note-cover {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: linear-gradient(135deg, #111827 0%, #002fa7 100%);
}

.note-cover.g2 { background: linear-gradient(135deg, #f8f9fb 0%, #d8dfed 100%); }
.note-cover.g3 { background: linear-gradient(135deg, #083344 0%, #0e7490 100%); }
.note-cover.g4 { background: linear-gradient(135deg, #1f2937 0%, #4b5563 100%); }
.note-cover.g5 { background: linear-gradient(135deg, #002fa7 0%, #4a6fe0 100%); }
.note-cover.g6 { background: linear-gradient(135deg, #f8f1e7 0%, #e9d8bd 100%); }
.note-cover.g7 { background: linear-gradient(135deg, #0f172a 0%, #334155 100%); }
.note-cover.g8 { background: linear-gradient(135deg, #eaf3ef 0%, #bfd8cb 100%); }

.cover-kicker {
  position: absolute;
  z-index: 2;
  left: 18px;
  bottom: 16px;
  color: rgba(255, 255, 255, 0.92);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: 0.08em;
}

.note-cover.g2 .cover-kicker,
.note-cover.g6 .cover-kicker,
.note-cover.g8 .cover-kicker {
  color: var(--ink);
}

.play-button {
  position: absolute;
  z-index: 2;
  top: 50%;
  left: 50%;
  width: 56px;
  height: 56px;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.94);
  color: var(--ikb);
  display: grid;
  place-items: center;
}

.duration {
  position: absolute;
  z-index: 2;
  right: 12px;
  bottom: 12px;
  padding: 3px 8px;
  border-radius: 5px;
  color: #fff;
  background: rgba(0, 0, 0, 0.7);
  font-size: 11px;
  font-weight: 650;
}

.note-body {
  padding: 22px 24px 24px;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-bottom: 12px;
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: 999px;
  color: var(--gray-5);
  background: var(--gray-2);
  font-size: 12px;
  line-height: 1.5;
}

.tag.blue {
  color: var(--ikb);
  background: var(--ikb-soft);
}

.tag.warm {
  color: #7c4a03;
  background: #fff3d6;
}

.note-title {
  margin: 0 0 9px;
  font-size: 18px;
  line-height: 1.42;
  letter-spacing: 0;
  font-weight: 700;
}

.note-excerpt {
  margin: 0 0 18px;
  color: var(--gray-5);
  font-size: 14px;
  line-height: 1.65;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
}

.meta {
  padding-top: 14px;
  border-top: 1px solid var(--gray-3);
  color: var(--gray-6);
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 12px;
}

.course-highlight {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 32px;
  align-items: stretch;
}

.course-panel {
  padding: 42px;
  border-radius: 20px;
  background: #fff;
  border: 1px solid var(--gray-3);
}

.course-panel h3 {
  margin: 0 0 16px;
  font-size: clamp(28px, 3.2vw, 42px);
  line-height: 1.2;
}

.course-panel p {
  color: var(--gray-5);
  margin: 0 0 26px;
}

.schedule-card {
  padding: 30px;
  border-radius: 20px;
  color: #fff;
  background: #111827;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 340px;
}

.schedule-card small {
  color: rgba(255, 255, 255, 0.6);
  font-weight: 650;
  letter-spacing: 0.08em;
}

.schedule-card strong {
  display: block;
  margin-top: 18px;
  font-size: 34px;
  line-height: 1.2;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: 28px;
}

.timeline-step {
  padding: 18px;
  border-radius: 14px;
  background: #fff;
  border: 1px solid var(--gray-3);
}

.timeline-step strong {
  display: block;
  color: var(--ikb);
  font-size: 13px;
}

.timeline-step span {
  display: block;
  margin-top: 7px;
  font-size: 14px;
  color: var(--ink-2);
}

.cta-band {
  padding: 86px 0;
  color: #fff;
  background: var(--ikb);
  text-align: center;
}

.cta-band h2 {
  margin: 0 auto 18px;
  max-width: 760px;
  font-size: clamp(32px, 4vw, 48px);
  line-height: 1.2;
}

.cta-band p {
  max-width: 620px;
  margin: 0 auto 34px;
  color: rgba(255, 255, 255, 0.78);
}

.footer {
  padding: 64px 0 34px;
  border-top: 1px solid var(--gray-3);
}

.footer-main {
  width: min(1200px, calc(100% - 48px));
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 44px;
}

.footer-brand {
  max-width: 340px;
}

.footer-brand p {
  color: var(--gray-5);
  font-size: 14px;
}

.footer-cols {
  display: flex;
  gap: 70px;
}

.footer-col h4 {
  margin: 0 0 14px;
  font-size: 13px;
}

.footer-col a {
  display: block;
  margin-bottom: 8px;
  color: var(--gray-5);
  font-size: 14px;
}

.footer-bottom {
  width: min(1200px, calc(100% - 48px));
  margin: 44px auto 0;
  padding-top: 22px;
  border-top: 1px solid var(--gray-3);
  color: var(--gray-6);
  font-size: 13px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.page-head {
  padding: 84px 0 46px;
}

.breadcrumb {
  margin-bottom: 16px;
  color: var(--gray-5);
  font-size: 14px;
}

.breadcrumb a:hover {
  color: var(--ikb);
}

.page-title {
  color: var(--ink);
}

.page-lead {
  max-width: 760px;
  margin: 22px 0 0;
  color: var(--gray-5);
  font-size: 18px;
}

.toolbar {
  position: sticky;
  top: 64px;
  z-index: 40;
  padding: 18px 0;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  border-top: 1px solid var(--gray-3);
  border-bottom: 1px solid var(--gray-3);
}

.toolbar-inner {
  width: min(1280px, calc(100% - 48px));
  margin: 0 auto;
  display: flex;
  gap: 18px;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}

.chips {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.chip {
  min-height: 36px;
  padding: 0 15px;
  border: 1px solid var(--gray-3);
  border-radius: 999px;
  background: #fff;
  color: var(--ink-2);
  cursor: pointer;
  font-size: 13px;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.chip:hover,
.chip.active {
  background: var(--ikb);
  color: #fff;
  border-color: var(--ikb);
}

.search-box {
  width: min(280px, 100%);
  height: 40px;
  border: 1px solid var(--gray-3);
  border-radius: 999px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 14px;
  background: var(--gray-1);
  color: var(--gray-5);
}

.search-box input {
  width: 100%;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
  font-size: 14px;
}

.course-hero {
  padding: 88px 0 82px;
  background: var(--gray-1);
}

.course-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 44px;
  align-items: start;
}

.course-title {
  color: var(--ink);
  max-width: 820px;
}

.course-sub {
  max-width: 710px;
  margin: 24px 0 34px;
  color: var(--gray-5);
  font-size: 18px;
}

.quick-info {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  max-width: 760px;
}

.quick-item {
  padding: 18px;
  border-radius: 14px;
  background: #fff;
  border: 1px solid var(--gray-3);
}

.quick-item span {
  display: block;
  color: var(--gray-5);
  font-size: 12px;
}

.quick-item strong {
  display: block;
  margin-top: 5px;
  font-size: 16px;
}

.enroll-card {
  position: sticky;
  top: 88px;
  padding: 28px;
  border-radius: 18px;
  background: #fff;
  border: 1px solid var(--gray-3);
  box-shadow: 0 20px 60px rgba(17, 24, 39, 0.08);
}

.price {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 6px;
}

.price strong {
  font-size: 38px;
  line-height: 1.1;
}

.price span {
  color: var(--gray-5);
}

.feature-list {
  list-style: none;
  padding: 20px 0 22px;
  margin: 0;
  display: grid;
  gap: 12px;
}

.feature-list li {
  display: flex;
  gap: 9px;
  color: var(--ink-2);
  font-size: 14px;
}

.feature-list svg {
  color: var(--ikb);
  flex: 0 0 auto;
  margin-top: 4px;
}

.course-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 48px;
}

.toc {
  position: sticky;
  top: 92px;
  align-self: start;
  padding: 22px;
  border-radius: 16px;
  border: 1px solid var(--gray-3);
  background: #fff;
}

.toc h3 {
  margin: 0 0 12px;
  font-size: 15px;
}

.toc a {
  display: block;
  padding: 8px 0;
  color: var(--gray-5);
  font-size: 14px;
}

.toc a:hover {
  color: var(--ikb);
}

.content-block {
  margin-bottom: 88px;
}

.content-block h2 {
  margin: 0 0 22px;
  font-size: clamp(30px, 3.5vw, 44px);
  line-height: 1.2;
}

.content-block > p {
  color: var(--gray-5);
  font-size: 17px;
}

.outcome-list {
  display: grid;
  gap: 14px;
  margin-top: 28px;
}

.outcome {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 18px;
  align-items: start;
  padding: 24px;
  border: 1px solid var(--gray-3);
  border-radius: 16px;
  background: #fff;
}

.outcome-num {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  color: var(--ikb);
  background: var(--ikb-soft);
  font-weight: 800;
}

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

.lesson {
  border: 1px solid var(--gray-3);
  border-radius: 16px;
  background: #fff;
  overflow: hidden;
}

.lesson summary {
  list-style: none;
  cursor: pointer;
  padding: 22px 24px;
  display: grid;
  grid-template-columns: 84px 1fr auto;
  gap: 18px;
  align-items: center;
}

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

.lesson-no {
  color: var(--ikb);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: 0.05em;
}

.lesson-title {
  font-size: 17px;
  font-weight: 700;
}

.lesson-body {
  padding: 0 24px 24px 126px;
  color: var(--gray-5);
}

.lesson-body ul {
  margin: 14px 0 0;
  padding-left: 18px;
}

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

.review-card {
  padding: 30px;
}

.review-card p {
  margin: 0 0 22px;
  color: var(--ink-2);
}

.reviewer {
  display: flex;
  gap: 12px;
  align-items: center;
}

.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--ikb);
  color: #fff;
  font-weight: 750;
}

.muted {
  color: var(--gray-5);
}

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

.faq details {
  border: 1px solid var(--gray-3);
  border-radius: 14px;
  background: #fff;
}

.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 20px 22px;
  font-weight: 700;
}

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

.faq div {
  padding: 0 22px 22px;
  color: var(--gray-5);
}

.work-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.work-visual {
  aspect-ratio: 4 / 3;
  display: grid;
  place-items: center;
  color: rgba(255, 255, 255, 0.92);
  font-weight: 750;
  background: linear-gradient(135deg, #111827, #3b82f6);
}

.work-card:nth-child(2n) .work-visual { background: linear-gradient(135deg, #083344, #0e7490); }
.work-card:nth-child(3n) .work-visual { background: linear-gradient(135deg, #7c4a03, #d69e2e); }
.work-card:nth-child(4n) .work-visual { background: linear-gradient(135deg, #1f2937, #6b7280); }

.work-body {
  padding: 22px;
}

.work-body h3 {
  margin: 0 0 6px;
  font-size: 18px;
}

.work-body p {
  margin: 0;
  color: var(--gray-5);
  font-size: 14px;
}

.about-grid {
  display: grid;
  grid-template-columns: 0.92fr 1.08fr;
  gap: 48px;
  align-items: start;
}

.portrait {
  min-height: 520px;
  border-radius: 20px;
  overflow: hidden;
  background:
    linear-gradient(180deg, rgba(0, 47, 167, 0.1), rgba(17, 24, 39, 0.66)),
    url("./ai-studio.jpg") center / cover no-repeat;
}

.story p {
  color: var(--ink-2);
  font-size: 17px;
}

.milestones {
  margin-top: 34px;
  display: grid;
  gap: 16px;
}

.milestone {
  display: grid;
  grid-template-columns: 86px 1fr;
  gap: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--gray-3);
}

.milestone strong {
  color: var(--ikb);
}

.qr-modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: none;
  place-items: center;
  padding: 24px;
  background: rgba(17, 24, 39, 0.46);
}

.qr-modal.open {
  display: grid;
}

.modal-card {
  width: min(760px, 100%);
  border-radius: 18px;
  background: #fff;
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.24);
  overflow: hidden;
}

.modal-head {
  padding: 24px 26px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--gray-3);
}

.modal-head h3 {
  margin: 0;
  font-size: 20px;
}

.modal-close {
  width: 36px;
  height: 36px;
  border: 1px solid var(--gray-3);
  border-radius: 50%;
  background: #fff;
  cursor: pointer;
}

.modal-body {
  padding: 28px;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 30px;
  align-items: center;
}

.modal-body img {
  width: 240px;
  border: 1px solid var(--gray-3);
  border-radius: 12px;
}

.modal-body p {
  color: var(--gray-5);
}

.empty-state {
  padding: 44px;
  border: 1px dashed var(--gray-3);
  border-radius: 16px;
  color: var(--gray-5);
  background: var(--gray-1);
}

@media (max-width: 960px) {
  .nav {
    width: min(100% - 32px, 1200px);
  }

  .nav-links {
    display: none;
  }

  .wrap,
  .wide,
  .stats-grid,
  .toolbar-inner,
  .footer-main,
  .footer-bottom {
    width: min(100% - 32px, 1200px);
  }

  .module-grid,
  .notes-grid,
  .course-grid,
  .works-grid,
  .audience-grid,
  .tutorial-hero-grid,
  .tutorial-grid,
  .prompt-grid,
  .timeline,
  .review-grid {
    grid-template-columns: 1fr;
  }

  .hero-topline,
  .board-toolbar {
    grid-template-columns: 1fr;
    align-items: start;
  }

  .hero-topline {
    flex-direction: column;
  }

  .tutorial-hero-copy {
    text-align: left;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .stat {
    border-right: 1px solid var(--gray-3);
  }

  .course-highlight,
  .course-hero-grid,
  .course-layout,
  .about-grid {
    grid-template-columns: 1fr;
  }

  .enroll-card,
  .toc {
    position: static;
  }

  .quick-info {
    grid-template-columns: 1fr;
  }

  .lesson summary {
    grid-template-columns: 1fr auto;
  }

  .lesson-no {
    grid-column: 1 / -1;
  }

  .lesson-body {
    padding-left: 24px;
  }

  .modal-body {
    grid-template-columns: 1fr;
  }

  .footer-main,
  .footer-cols {
    flex-direction: column;
  }
}

@media (max-width: 560px) {
  .hero {
    min-height: 74vh;
    padding-top: 92px;
  }

  .section {
    padding: 78px 0;
  }

  .stats-grid {
    grid-template-columns: 1fr;
  }

  .toolbar {
    position: static;
  }

  .search-box {
    width: 100%;
  }
}