/* ============================================================
   HKOEA — Base & Layout
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

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

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

button {
  font: inherit;
  cursor: pointer;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  line-height: 1.14;
  letter-spacing: -0.022em;
  font-weight: 600;
}

p {
  margin: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

/* ---- 焦點樣式（a11y 必須保留） ---- */
:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
  border-radius: 4px;
}

::selection {
  background: var(--gold);
  color: #0b0b0c;
}

/* ============================================================
   容器
   ============================================================ */

.wrap {
  width: 100%;
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: var(--section-y);
  position: relative;
}

.section + .section {
  border-top: var(--hair);
}

/* ============================================================
   字級
   ============================================================ */

.display {
  font-size: clamp(2.5rem, 6.6vw, 4.75rem);
  line-height: 1.03;
  letter-spacing: -0.035em;
  font-weight: 600;
}

.h1 {
  font-size: clamp(2.1rem, 4.6vw, 3.4rem);
  letter-spacing: -0.03em;
}

.h2 {
  font-size: clamp(1.65rem, 3.2vw, 2.5rem);
  letter-spacing: -0.028em;
}

.h3 {
  font-size: clamp(1.15rem, 1.6vw, 1.4rem);
  letter-spacing: -0.018em;
}

.lead {
  font-size: clamp(1.02rem, 1.35vw, 1.2rem);
  line-height: 1.62;
  color: var(--ink2);
}

.body {
  color: var(--ink2);
}

.small {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.6;
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold);
}

.gold {
  color: var(--gold);
}

.italic-gold {
  font-style: italic;
  color: var(--gold);
  font-weight: 400;
}

/* ============================================================
   眉標
   ============================================================ */

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 18px;
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--gold);
  opacity: 0.7;
}

/* ============================================================
   按鈕
   ============================================================ */

.btn {
  --btn-bg: transparent;
  --btn-fg: var(--ink);
  --btn-bd: var(--line);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 14px 26px;
  border-radius: 999px;
  border: 1px solid var(--btn-bd);
  background: var(--btn-bg);
  color: var(--btn-fg);
  font-size: 0.925rem;
  font-weight: 500;
  letter-spacing: 0.005em;
  transition: transform 0.24s var(--ease), background-color 0.24s var(--ease),
    border-color 0.24s var(--ease), color 0.24s var(--ease), box-shadow 0.24s var(--ease);
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

.btn--primary {
  --btn-bg: var(--gold);
  --btn-fg: #0b0b0c;
  --btn-bd: var(--gold);
  font-weight: 600;
}

.btn--primary:hover {
  --btn-bg: var(--gold-lt);
  --btn-bd: var(--gold-lt);
  box-shadow: 0 12px 30px rgba(217, 180, 81, 0.26);
}

html[data-theme="light"] .btn--primary {
  --btn-bg: var(--gold-deep);
  --btn-bd: var(--gold-deep);
  --btn-fg: #ffffff;
}

.btn--ghost:hover {
  --btn-bd: var(--gold);
  --btn-fg: var(--gold);
}

.btn--sm {
  padding: 10px 18px;
  font-size: 0.85rem;
}

.btn .arrow {
  transition: transform 0.24s var(--ease);
}

.btn:hover .arrow {
  transform: translateX(3px);
}

/* ---- 文字連結 ---- */
.link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  color: var(--gold);
  font-size: 0.9rem;
  font-weight: 500;
  border-bottom: 1px solid transparent;
  transition: border-color 0.24s var(--ease), gap 0.24s var(--ease);
}

.link:hover {
  border-bottom-color: var(--gold);
  gap: 11px;
}

/* ============================================================
   卡片
   ============================================================ */

.card {
  background: var(--panel);
  border: var(--hair);
  border-radius: var(--radius);
  padding: clamp(22px, 2.6vw, 32px);
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease),
    box-shadow 0.3s var(--ease), background-color 0.3s var(--ease);
}

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

/* ============================================================
   分格線 / 標籤
   ============================================================ */

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 11px;
  border-radius: 6px;
  border: 1px solid var(--line2);
  background: var(--panel2);
  font-size: 0.745rem;
  letter-spacing: 0.02em;
  color: var(--muted);
  /* 標籤預設不換行，但技能標籤可能很長（如 R11 的
     "Fluent hands-on operation of at least two general-purpose agents"），
     不換行會把整個 grid 欄撐開，令手機版出現橫向捲軸。
     故允許換行並限制最大寬度。 */
  white-space: normal;
  max-width: 100%;
  overflow-wrap: break-word;
}

.tag--gold {
  border-color: var(--line);
  color: var(--gold);
  background: transparent;
}

/* ============================================================
   捲動進場
   ============================================================ */

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
  will-change: opacity, transform;
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ============================================================
   跳至內容（a11y）
   ============================================================ */

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 200;
  padding: 12px 20px;
  background: var(--gold);
  color: #0b0b0c;
  border-radius: 0 0 8px 0;
  font-weight: 600;
}

.skip:focus {
  left: 0;
}

/* ============================================================
   工具類
   ============================================================ */

.grid {
  display: grid;
  gap: clamp(18px, 2vw, 26px);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}