/* =========================================================
   base
   ========================================================= */
:root {
  --color-bg: #1a1a1a;
  --color-surface: #2d2d2d;
  --color-surface-light: #363636;
  --color-text: #f5f5f5;
  --color-text-dim: #b8b8b8;
  --color-accent: #ff6b35;
  --color-accent-dark: #e55a2b;
  --color-border: #444444;
  --color-white: #ffffff;
  --font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --container-width: 1200px;
  --container-padding: 20px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 8px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --header-height: 64px;
  --touch-target: 44px;
}

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

html {
  font-size: 16px;
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-accent-dark);
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-white);
}

h1 {
  font-size: 28px;
}

h2 {
  font-size: 22px;
}

h3 {
  font-size: 18px;
}

p {
  margin-bottom: 12px;
}

/* =========================================================
   layout
   ========================================================= */
.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.site-main {
  flex: 1;
  width: 100%;
}

.site-main.inner-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  width: 100%;
}

/* ---------- header ---------- */
.site-header {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
}

.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-height);
  gap: 16px;
}

.brand-logo {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  flex-shrink: 0;
}

.brand-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: 0.5px;
}

.brand-slogan {
  font-size: 12px;
  color: var(--color-text-dim);
  margin-top: 2px;
}

/* ---------- navigation ---------- */
.site-nav {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-item a {
  display: block;
  padding: 10px 14px;
  color: var(--color-text-dim);
  font-size: 15px;
  border-radius: var(--radius-sm);
  min-height: var(--touch-target);
  line-height: 1.4;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.nav-item a:hover {
  color: var(--color-white);
  background-color: var(--color-surface-light);
}

.nav-item.is-current a,
.nav-item a.is-current {
  color: var(--color-accent);
  background-color: rgba(255, 107, 53, 0.12);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: var(--touch-target);
  height: var(--touch-target);
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 8px;
  gap: 5px;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--color-white);
  border-radius: 1px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* ---------- footer ---------- */
.site-footer {
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
  margin-top: 48px;
  width: 100%;
}

.footer-columns {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px var(--container-padding) 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.footer-col h3 {
  font-size: 16px;
  margin-bottom: 14px;
  color: var(--color-white);
}

.footer-col ul li {
  margin-bottom: 8px;
}

.footer-col ul li a {
  color: var(--color-text-dim);
  font-size: 14px;
  line-height: 1.5;
  display: inline-block;
  padding: 4px 0;
}

.footer-col ul li a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding: 16px var(--container-padding);
  text-align: center;
}

.footer-bottom p {
  font-size: 13px;
  color: var(--color-text-dim);
  margin-bottom: 0;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
}

/* ---------- breadcrumb ---------- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 20px 0 16px;
  font-size: 14px;
  color: var(--color-text-dim);
  flex-wrap: wrap;
}

.breadcrumb a {
  color: var(--color-text-dim);
}

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

.breadcrumb-sep {
  color: var(--color-border);
}

.breadcrumb-current {
  color: var(--color-white);
}

/* ---------- page header ---------- */
.page-header {
  padding: 8px 0 28px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 32px;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 10px;
}

.page-description {
  font-size: 15px;
  color: var(--color-text-dim);
  line-height: 1.7;
  max-width: 720px;
  margin-bottom: 0;
}

/* ---------- section title ---------- */
.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 16px;
  position: relative;
  padding-left: 14px;
}

.section-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  background-color: var(--color-accent);
  border-radius: 2px;
}

.section-intro {
  font-size: 15px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 24px;
  max-width: 760px;
}

/* =========================================================
   components
   ========================================================= */

/* ---------- section title variants ---------- */
.module-title,
.tag-index-title,
.category-links-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 16px;
}

.module-intro {
  font-size: 15px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 20px;
  max-width: 760px;
}

/* ---------- more link ---------- */
.more-link {
  margin-top: 16px;
  text-align: right;
}

.more-link a {
  display: inline-block;
  padding: 8px 16px;
  color: var(--color-accent);
  font-size: 14px;
  font-weight: 600;
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-sm);
  min-height: var(--touch-target);
  line-height: 1.4;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.more-link a:hover {
  background-color: var(--color-accent);
  color: var(--color-white);
}

/* ---------- hero (index) ---------- */
.hero-dir {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 32px var(--container-padding) 40px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
}

.hero-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hero-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--color-white);
  line-height: 1.25;
  margin-bottom: 16px;
}

.hero-lead {
  font-size: 16px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 24px;
  max-width: 480px;
}

.hero-cta {
  display: inline-block;
  padding: 12px 28px;
  background-color: var(--color-accent);
  color: var(--color-white);
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  min-height: var(--touch-target);
  line-height: 1.4;
  align-self: flex-start;
  transition: background-color var(--transition-fast);
}

.hero-cta:hover {
  background-color: var(--color-accent-dark);
  color: var(--color-white);
}

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-visual img {
  width: 100%;
  max-width: 520px;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.hero-category-index {
  grid-column: 1;
}

.hero-update-list {
  grid-column: 2;
}

.hero-category-index .section-title,
.hero-update-list .section-title {
  font-size: 18px;
}

.hero-tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.hero-tag-list li a {
  display: inline-flex;
  align-items: center;
  min-height: var(--touch-target);
  padding: 8px 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-size: 14px;
  transition: border-color var(--transition-fast), color var(--transition-fast), background-color var(--transition-fast);
}

.hero-tag-list li a:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background-color: rgba(255, 107, 53, 0.08);
}

.update-mini-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--color-border);
}

.update-mini-list li:last-child {
  border-bottom: none;
}

.update-mini-list li a {
  color: var(--color-text);
  font-size: 14px;
  line-height: 1.5;
  flex: 1;
}

.update-mini-list li a:hover {
  color: var(--color-accent);
}

.update-mini-list time {
  font-size: 13px;
  color: var(--color-text-dim);
  flex-shrink: 0;
}

/* ---------- category tags (index) ---------- */
.category-tags {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px var(--container-padding) 8px;
}

.tag-scroll {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag-item {
  display: inline-flex;
  align-items: center;
  min-height: var(--touch-target);
  padding: 8px 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-size: 14px;
  transition: border-color var(--transition-fast), color var(--transition-fast), background-color var(--transition-fast);
}

.tag-item:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background-color: rgba(255, 107, 53, 0.08);
}

/* ---------- recent updates (index) ---------- */
.recent-updates {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px var(--container-padding);
}

.update-group {
  margin-bottom: 28px;
}

.update-date {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.update-items {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}

.update-item {
  display: flex;
  gap: 12px;
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 12px;
  min-width: 0;
}

.update-item img {
  width: 72px;
  height: 96px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.update-info {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-width: 0;
}

.update-info h4 {
  font-size: 15px;
  color: var(--color-white);
  line-height: 1.4;
  margin-bottom: 6px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.update-time {
  font-size: 13px;
  color: var(--color-text-dim);
}

/* ---------- ranking preview (index) ---------- */
.ranking-preview {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px var(--container-padding);
}

.ranking-preview .ranking-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}

.ranking-preview .ranking-item {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}

.rank-num {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
}

.ranking-preview .ranking-item img {
  width: 100%;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

.rank-info {
  min-width: 0;
}

.rank-info h3 {
  font-size: 16px;
  line-height: 1.4;
  margin-bottom: 6px;
}

.rank-info h3 a {
  color: var(--color-white);
}

.rank-info h3 a:hover {
  color: var(--color-accent);
}

.rank-reason {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.6;
  margin-bottom: 0;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ---------- guide entry (index) ---------- */
.guide-entry {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px var(--container-padding);
}

.guide-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.guide-card {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid var(--color-border);
  transition: border-color var(--transition-fast);
}

.guide-card:hover {
  border-color: var(--color-accent);
}

.guide-card h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

.guide-card h3 a {
  color: var(--color-white);
}

.guide-card h3 a:hover {
  color: var(--color-accent);
}

.guide-card p {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.6;
  margin-bottom: 0;
}

/* ---------- copyright note (index) ---------- */
.copyright-note {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px var(--container-padding) 8px;
}

.copyright-note .section-title {
  font-size: 18px;
}

.copyright-note p {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 8px;
  max-width: 860px;
}

/* ---------- category page ---------- */
.tag-index {
  margin-bottom: 40px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag-list li a {
  display: inline-flex;
  align-items: center;
  min-height: var(--touch-target);
  padding: 8px 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-size: 14px;
  transition: border-color var(--transition-fast), color var(--transition-fast), background-color var(--transition-fast);
}

.tag-list li a:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background-color: rgba(255, 107, 53, 0.08);
}

.category-sections {
  display: flex;
  flex-direction: column;
  gap: 48px;
}

.category-section {
  scroll-margin-top: 80px;
}

.category-heading {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 8px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

.category-desc {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.6;
  margin-bottom: 20px;
  max-width: 760px;
}

.category-card {
  display: flex;
  gap: 16px;
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 16px;
  max-width: 640px;
}

.card-cover {
  width: 96px;
  height: 128px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.card-body {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-width: 0;
}

.card-body h3 {
  font-size: 17px;
  color: var(--color-white);
  margin-bottom: 8px;
}

.card-body p {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.6;
  margin-bottom: 10px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-body a {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
  align-self: flex-start;
}

.card-body a:hover {
  color: var(--color-accent-dark);
}

.category-links {
  margin-top: 48px;
  padding: 24px;
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
}

.category-links p {
  font-size: 15px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 8px;
}

.category-links p a {
  display: inline-block;
  margin-right: 16px;
  padding: 6px 0;
  font-weight: 600;
}

/* ---------- guide page ---------- */
.guide-section {
  margin-bottom: 48px;
}

.steps-list {
  counter-reset: step-counter;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.step-item {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 24px;
  position: relative;
  border: 1px solid var(--color-border);
}

.step-item::before {
  counter-increment: step-counter;
  content: counter(step-counter, decimal-leading-zero);
  position: absolute;
  top: 16px;
  right: 16px;
  font-size: 24px;
  font-weight: 700;
  color: var(--color-accent);
  opacity: 0.7;
  line-height: 1;
}

.step-title {
  font-size: 17px;
  color: var(--color-white);
  margin-bottom: 10px;
  padding-right: 40px;
}

.step-text {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 0;
}

.reading-media {
  margin-bottom: 24px;
}

.reading-figure {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.reading-figure img {
  width: 100%;
  max-width: 640px;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.reading-figure figcaption {
  font-size: 13px;
  color: var(--color-text-dim);
  text-align: center;
}

.reading-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.reading-step-block {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 20px;
  border: 1px solid var(--color-border);
}

.reading-step-block .step-title {
  font-size: 16px;
  padding-right: 0;
}

.reading-step-block .step-text {
  font-size: 14px;
}

.device-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.device-card {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid var(--color-border);
  transition: border-color var(--transition-fast);
}

.device-card:hover {
  border-color: var(--color-accent);
}

.device-title {
  font-size: 17px;
  color: var(--color-white);
  margin-bottom: 12px;
}

.device-text {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 0;
}

.faq-item {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  border: 1px solid var(--color-border);
  overflow: hidden;
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-white);
  cursor: pointer;
  list-style: none;
  min-height: var(--touch-target);
  gap: 16px;
}

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

.faq-question::after {
  content: "+";
  font-size: 22px;
  font-weight: 400;
  color: var(--color-accent);
  flex-shrink: 0;
  transition: transform var(--transition-fast);
}

.faq-item[open] .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  padding: 0 20px 16px;
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 0;
}

.related-links {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
}

.related-links li a {
  display: flex;
  align-items: center;
  min-height: var(--touch-target);
  padding: 12px 16px;
  background-color: var(--color-surface);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-size: 14px;
  border: 1px solid var(--color-border);
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.related-links li a:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ---------- ranking page ---------- */
.ranking-section {
  margin-bottom: 48px;
}

.ranking-section .ranking-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.ranking-section .ranking-item {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.ranking-card {
  display: flex;
  gap: 20px;
  padding: 16px;
  align-items: flex-start;
}

.ranking-num {
  font-size: 36px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  width: 48px;
  flex-shrink: 0;
  text-align: center;
  padding-top: 4px;
}

.ranking-cover {
  flex-shrink: 0;
}

.ranking-cover img {
  width: 80px;
  height: 106px;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

.ranking-info {
  flex: 1;
  min-width: 0;
}

.ranking-name {
  font-size: 18px;
  color: var(--color-white);
  margin-bottom: 6px;
}

.ranking-tag {
  display: inline-block;
  padding: 3px 10px;
  background-color: rgba(255, 107, 53, 0.15);
  color: var(--color-accent);
  font-size: 13px;
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
}

.ranking-desc {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.6;
  margin-bottom: 6px;
}

.ranking-reason {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.6;
  margin-bottom: 0;
  background-color: rgba(255, 255, 255, 0.04);
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-accent);
}

.ranking-notes {
  margin-bottom: 48px;
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 24px;
}

.notes-content p {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 10px;
}

.notes-content p:last-child {
  margin-bottom: 0;
}

.related-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
}

.related-list li a {
  display: flex;
  align-items: center;
  min-height: var(--touch-target);
  padding: 12px 16px;
  background-color: var(--color-surface);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-size: 14px;
  border: 1px solid var(--color-border);
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.related-list li a:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ---------- update page ---------- */
.module-block {
  margin-bottom: 48px;
}

.update-list .update-group {
  margin-bottom: 32px;
}

.update-list .update-date {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.update-list .update-items {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
}

.update-list .update-item {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  overflow: hidden;
  min-width: 0;
}

.update-link {
  display: flex;
  gap: 12px;
  padding: 12px;
  align-items: center;
  min-height: var(--touch-target);
}

.update-link:hover {
  background-color: var(--color-surface-light);
}

.update-thumb {
  width: 64px;
  height: 85px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.update-info {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-width: 0;
  gap: 4px;
}

.update-info a {
  color: var(--color-text);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.update-info a:hover {
  color: var(--color-accent);
}

.update-time {
  font-size: 13px;
  color: var(--color-text-dim);
}

.update-note {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 24px;
}

.update-note p {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 10px;
}

.update-note p:last-child {
  margin-bottom: 0;
}

/* ---------- tips page ---------- */
.tips-section {
  margin-bottom: 48px;
}

.tips-section .section-title {
  margin-top: 32px;
}

.tips-section .section-title:first-child {
  margin-top: 0;
}

.tips-section p {
  font-size: 15px;
  color: var(--color-text-dim);
  line-height: 1.8;
  margin-bottom: 16px;
  max-width: 780px;
}

.tips-section p:last-child {
  margin-bottom: 0;
}

.tips-flow {
  margin-bottom: 48px;
}

.tips-figure {
  margin-bottom: 20px;
}

.tips-figure img {
  width: 100%;
  max-width: 680px;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.tips-figure figcaption {
  font-size: 13px;
  color: var(--color-text-dim);
  margin-top: 8px;
}

.tips-flow p {
  font-size: 15px;
  color: var(--color-text-dim);
  line-height: 1.8;
  max-width: 780px;
}

.tips-advice {
  margin-bottom: 48px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.tips-advice .section-title {
  grid-column: 1 / -1;
}

.advice-card {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid var(--color-border);
  transition: border-color var(--transition-fast);
}

.advice-card:hover {
  border-color: var(--color-accent);
}

.advice-card h3 {
  font-size: 17px;
  color: var(--color-white);
  margin-bottom: 10px;
}

.advice-card p {
  font-size: 14px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 0;
}

.tips-summary {
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 32px 24px;
}

.tips-summary p {
  font-size: 15px;
  color: var(--color-text-dim);
  line-height: 1.8;
  margin-bottom: 14px;
  max-width: 780px;
}

.tips-summary p:last-child {
  margin-bottom: 0;
}

.tips-summary p a {
  display: inline-block;
  margin-right: 12px;
  font-weight: 600;
}

/* ---------- 404 page ---------- */
.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 20px;
  flex: 1;
}

.error-panel {
  text-align: center;
  max-width: 520px;
  width: 100%;
}

.error-code {
  font-size: 72px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 16px;
}

.error-panel h1 {
  font-size: 28px;
  margin-bottom: 16px;
}

.error-desc {
  font-size: 15px;
  color: var(--color-text-dim);
  line-height: 1.7;
  margin-bottom: 28px;
}

.error-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  background-color: var(--color-accent);
  color: var(--color-white);
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  min-height: var(--touch-target);
  transition: background-color var(--transition-fast);
}

.error-action:hover {
  background-color: var(--color-accent-dark);
  color: var(--color-white);
}

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

  .hero-dir {
    gap: 24px;
  }

  .reading-steps,
  .device-cards {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  :root {
    --container-padding: 16px;
  }

  .site-header {
    position: sticky;
  }

  .header-inner {
    flex-wrap: wrap;
    min-height: var(--header-height);
    padding-top: 8px;
    padding-bottom: 8px;
  }

  .nav-toggle {
    display: flex;
    order: 3;
    margin-left: auto;
  }

  .brand-logo {
    order: 1;
  }

  .site-nav {
    order: 4;
    width: 100%;
    flex-basis: 100%;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    width: 100%;
    gap: 0;
    padding: 8px 0;
  }

  .nav-list.is-open {
    display: flex;
  }

  .nav-item {
    width: 100%;
  }

  .nav-item a {
    padding: 14px 12px;
    font-size: 15px;
    border-radius: var(--radius-sm);
  }

  .site-main.inner-main {
    padding: 0 var(--container-padding);
  }

  .hero-dir {
    grid-template-columns: 1fr;
    gap: 24px;
    padding-top: 24px;
  }

  .hero-copy {
    order: 1;
  }

  .hero-visual {
    order: 2;
  }

  .hero-category-index {
    grid-column: 1;
    order: 3;
  }

  .hero-update-list {
    grid-column: 1;
    order: 4;
  }

  .hero-title {
    font-size: 26px;
  }

  .hero-lead {
    font-size: 15px;
  }

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

  .steps-list {
    grid-template-columns: 1fr;
  }

  .reading-steps {
    grid-template-columns: 1fr;
  }

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

  .tips-advice {
    grid-template-columns: 1fr;
  }

  .category-card {
    flex-direction: column;
    max-width: 100%;
  }

  .card-cover {
    width: 100%;
    height: auto;
    aspect-ratio: 16 / 9;
    object-fit: cover;
  }

  .ranking-card {
    flex-wrap: wrap;
    gap: 12px;
  }

  .ranking-num {
    width: 100%;
    text-align: left;
    font-size: 28px;
  }

  .ranking-cover img {
    width: 72px;
    height: 96px;
  }

  .ranking-info {
    flex-basis: calc(100% - 92px);
  }

  .footer-columns {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }

  .page-header {
    padding: 8px 0 20px;
    margin-bottom: 24px;
  }

  .page-title {
    font-size: 24px;
  }

  .section-title {
    font-size: 20px;
  }

  .update-items {
    grid-template-columns: 1fr;
  }

  .update-list .update-items {
    grid-template-columns: 1fr;
  }

  .hero-tag-list {
    gap: 8px;
  }

  .hero-tag-list li a {
    padding: 8px 12px;
    font-size: 13px;
  }

  .tag-scroll {
    gap: 8px;
  }

  .tag-item {
    padding: 8px 12px;
    font-size: 13px;
  }

  .tag-list {
    gap: 8px;
  }

  .tag-list li a {
    padding: 8px 12px;
    font-size: 13px;
  }

  .breadcrumb {
    padding: 16px 0 12px;
    font-size: 13px;
  }

  .error-main {
    padding: 48px 16px;
  }

  .error-code {
    font-size: 56px;
  }
}

@media (max-width: 480px) {
  .footer-columns {
    grid-template-columns: 1fr;
    gap: 20px;
    padding-top: 28px;
  }

  .ranking-preview .ranking-list {
    grid-template-columns: 1fr;
  }

  .update-items {
    grid-template-columns: 1fr;
  }

  .update-list .update-items {
    grid-template-columns: 1fr;
  }

  .related-links {
    grid-template-columns: 1fr;
  }

  .related-list {
    grid-template-columns: 1fr;
  }

  .ranking-info {
    flex-basis: 100%;
  }

  .ranking-card {
    flex-direction: column;
  }

  .ranking-cover img {
    width: 100%;
    height: auto;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    max-width: 160px;
  }

  .hero-cta {
    width: 100%;
    text-align: center;
  }

  .guide-card {
    padding: 20px;
  }

  .step-item {
    padding: 20px;
  }

  .device-card {
    padding: 20px;
  }

  .advice-card {
    padding: 20px;
  }
}

/* ---------- scroll reveal (progressive enhancement) ---------- */
@media (prefers-reduced-motion: no-preference) {
  .category-tags,
  .recent-updates,
  .ranking-preview,
  .guide-entry,
  .category-section,
  .guide-section,
  .ranking-section,
  .module-block,
  .tips-section,
  .tips-flow,
  .tips-advice,
  .tips-summary {
    animation: fade-up 0.5s ease both;
  }
}

@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .category-tags,
  .recent-updates,
  .ranking-preview,
  .guide-entry,
  .category-section,
  .guide-section,
  .ranking-section,
  .module-block,
  .tips-section,
  .tips-flow,
  .tips-advice,
  .tips-summary {
    animation: none;
  }
}