/* ============================================================
   Delta ½ — 深色設計系統
   主色：夜海深藍底 + 燦金黃點綴
   ============================================================ */

:root {
  --bg: #0a0d14;
  --bg-soft: #0d1119;
  --bg-card: #111722;
  --bg-card-hover: #151c2a;
  --border: #1d2532;
  --border-soft: #232c3b;

  --yellow: #f2c300;
  --yellow-bright: #ffd52e;
  --yellow-dim: rgba(242, 195, 0, 0.12);

  --text: #eef2f8;
  --text-soft: #c4ccda;
  --text-muted: #8a94a8;
  --text-faint: #5d6778;

  --red: #ff4d4f;
  --green: #2ecc71;
  --blue: #5b9cf5;

  --radius: 14px;
  --radius-lg: 20px;
  --maxw: 1180px;

  --font-sans: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei",
    -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  letter-spacing: 0.2px;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* 背景微光 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(242, 195, 0, 0.06), transparent 60%),
    radial-gradient(900px 500px at -10% 20%, rgba(91, 156, 245, 0.05), transparent 55%);
  pointer-events: none;
  z-index: 0;
}

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

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

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 28px;
  position: relative;
  z-index: 1;
}

/* ============ Header / 導覽列 ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 13, 20, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: baseline;
  font-weight: 800;
  font-size: 24px;
  letter-spacing: -0.5px;
  white-space: nowrap;
}

.brand .delta {
  color: var(--text);
}

.brand .half {
  color: var(--yellow);
  margin-left: 1px;
  font-weight: 700;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
  flex: 1;
  justify-content: center;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 14.5px;
  padding: 8px 14px;
  border-radius: 8px;
  transition: color 0.2s, background 0.2s;
  white-space: nowrap;
}

.nav-links a:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.04);
}

.nav-links a.active {
  color: var(--yellow);
  background: var(--yellow-dim);
}

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

.socials .yt {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: rgba(255, 77, 79, 0.12);
  border: 1px solid rgba(255, 77, 79, 0.35);
  transition: transform 0.2s, background 0.2s;
}

.socials .yt svg {
  width: 20px;
  height: 20px;
  fill: var(--red);
}

.socials .tg {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-soft);
  transition: transform 0.2s, background 0.2s;
}

.socials .tg svg {
  width: 20px;
  height: 20px;
  fill: #d6e3f5;
}

.socials a:hover {
  transform: translateY(-2px);
  background: rgba(255, 255, 255, 0.1);
}

/* 行動版漢堡選單 */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: 0.25s;
}

/* ============ Hero ============ */
.hero {
  min-height: calc(100vh - 70px);
  display: flex;
  align-items: center;
  text-align: center;
  padding: 72px 0 56px;
}

.hero-inner {
  max-width: 900px;
  margin: 0 auto;
}

.hero .eyebrow {
  display: inline-block;
  font-size: 13px;
  letter-spacing: 3px;
  color: var(--yellow);
  border: 1px solid rgba(242, 195, 0, 0.35);
  border-radius: 100px;
  padding: 6px 18px;
  margin-bottom: 28px;
  background: var(--yellow-dim);
}

.hero h1 {
  font-size: clamp(30px, 5vw, 54px);
  font-weight: 800;
  line-height: 1.3;
  color: var(--yellow);
  letter-spacing: 0.5px;
}

.hero .sub {
  margin-top: 22px;
  font-size: clamp(22px, 3.5vw, 38px);
  font-weight: 700;
  line-height: 1.4;
}

.hero .sub .dim {
  color: var(--text);
}

.hero .sub .hl {
  color: var(--yellow);
}

.hero .lead {
  margin-top: 20px;
  color: var(--text-muted);
  font-size: 16.5px;
  max-width: 620px;
  margin-left: auto;
  margin-right: auto;
}

.hero-cta {
  margin-top: 40px;
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ============ 按鈕 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 15px 34px;
  font-size: 17px;
  font-weight: 700;
  border-radius: 12px;
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: transform 0.18s, box-shadow 0.18s, background 0.18s;
  line-height: 1;
}

.btn-primary {
  background: var(--yellow);
  color: #141207;
  box-shadow: 0 8px 26px rgba(242, 195, 0, 0.25);
}

.btn-primary:hover {
  background: var(--yellow-bright);
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(242, 195, 0, 0.35);
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: #3a4356;
}

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

.btn-sm {
  padding: 11px 22px;
  font-size: 15px;
}

/* ============ 統計列 ============ */
.stats {
  margin-top: 64px;
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

.stat {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 44px;
  min-width: 220px;
}

.stat .num {
  font-size: 42px;
  font-weight: 800;
  color: var(--yellow);
  line-height: 1;
}

.stat .label {
  margin-top: 10px;
  color: var(--text-muted);
  font-size: 15px;
  letter-spacing: 1px;
}

/* ============ 內容頁通用 ============ */
.page-hero {
  padding: 84px 0 40px;
  text-align: center;
}

.page-hero .eyebrow {
  display: inline-block;
  font-size: 13px;
  letter-spacing: 3px;
  color: var(--yellow);
  margin-bottom: 16px;
}

.page-hero h1 {
  font-size: clamp(30px, 4.5vw, 46px);
  font-weight: 800;
  color: var(--text);
}

.page-hero h1 .hl {
  color: var(--yellow);
}

.page-hero p {
  margin-top: 16px;
  color: var(--text-muted);
  font-size: 17px;
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

.section {
  padding: 48px 0;
}

.section-title {
  font-size: 26px;
  font-weight: 800;
  margin-bottom: 8px;
}

.section-title .hl {
  color: var(--yellow);
}

.section-desc {
  color: var(--text-muted);
  font-size: 15.5px;
  margin-bottom: 32px;
}

/* ============ 卡片 ============ */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px;
  transition: border-color 0.2s, transform 0.2s, background 0.2s;
}

.card:hover {
  border-color: #2c3850;
  background: var(--bg-card-hover);
  transform: translateY(-3px);
}

.card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.card .card-num {
  font-size: 13px;
  color: var(--yellow);
  letter-spacing: 2px;
  font-weight: 700;
  margin-bottom: 8px;
  display: block;
}

.grid {
  display: grid;
  gap: 22px;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

/* ============ 預測大卡 ============ */
.pred-hero-card {
  background: linear-gradient(160deg, #121a2a 0%, #0e1420 100%);
  border: 1px solid #24314a;
  border-radius: var(--radius-lg);
  padding: 40px 44px;
  text-align: center;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
}

.pred-price {
  font-size: clamp(44px, 7vw, 72px);
  font-weight: 800;
  color: var(--text);
  line-height: 1;
  letter-spacing: -1px;
}

.pred-change {
  display: inline-block;
  margin-top: 12px;
  font-size: 20px;
  font-weight: 700;
  padding: 5px 16px;
  border-radius: 100px;
}

.pred-change.up { color: var(--red); background: rgba(255, 77, 79, 0.12); }
.pred-change.down { color: var(--green); background: rgba(46, 204, 113, 0.12); }

.badge-buy {
  display: inline-block;
  margin-top: 18px;
  font-size: 20px;
  font-weight: 800;
  color: #141207;
  background: var(--yellow);
  padding: 8px 26px;
  border-radius: 100px;
}

.badge-sell {
  display: inline-block;
  margin-top: 18px;
  font-size: 20px;
  font-weight: 800;
  color: #eafff2;
  background: var(--green);
  padding: 8px 26px;
  border-radius: 100px;
}

.pred-meta {
  margin-top: 22px;
  display: flex;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
  color: var(--text-muted);
  font-size: 14.5px;
}

.pred-meta b {
  color: var(--text);
  font-weight: 600;
}

/* 準確率環 */
.accuracy-ring {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 26px;
  flex-wrap: wrap;
}

.ring {
  --p: 52.92;
  width: 170px;
  height: 170px;
  border-radius: 50%;
  background: conic-gradient(var(--yellow) calc(var(--p) * 1%), #1c2534 0);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.ring::before {
  content: "";
  position: absolute;
  inset: 16px;
  border-radius: 50%;
  background: var(--bg-card);
}

.ring .val {
  position: relative;
  text-align: center;
}

.ring .val .pct {
  font-size: 34px;
  font-weight: 800;
  color: var(--yellow);
  line-height: 1;
}

.ring .val .cap {
  font-size: 12.5px;
  color: var(--text-muted);
  margin-top: 6px;
}

/* ============ 表格 ============ */
.tbl-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14.5px;
  min-width: 560px;
}

thead th {
  background: #131a27;
  color: var(--text-muted);
  font-weight: 600;
  text-align: left;
  padding: 13px 16px;
  font-size: 13px;
  letter-spacing: 0.5px;
  border-bottom: 1px solid var(--border);
}

tbody td {
  padding: 13px 16px;
  border-bottom: 1px solid var(--border-soft);
  color: var(--text-soft);
}

tbody tr:last-child td { border-bottom: none; }
tbody tr:hover td { background: rgba(255, 255, 255, 0.02); }

.tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 11px;
  border-radius: 100px;
  letter-spacing: 0.5px;
}

.tag.yellow { background: var(--yellow-dim); color: var(--yellow); }
.tag.blue { background: rgba(91, 156, 245, 0.14); color: var(--blue); }
.tag.green { background: rgba(46, 204, 113, 0.14); color: var(--green); }

/* ============ 過去績效圖片 ============ */
.perf-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 22px;
}

.perf-item {
  background: #fff;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  transition: transform 0.2s, box-shadow 0.2s;
}

.perf-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 18px 44px rgba(0, 0, 0, 0.5);
}

.perf-item img {
  width: 100%;
  height: auto;
}

.perf-item .cap {
  padding: 14px 18px;
  font-size: 14px;
  color: var(--text-muted);
  background: var(--bg-card);
  border-top: 1px solid var(--border);
}

/* ============ 引用/強調 ============ */
.pullquote {
  border-left: 4px solid var(--yellow);
  background: var(--bg-card);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 26px 30px;
  font-size: 19px;
  color: var(--text-soft);
  margin: 20px 0;
}

.pullquote strong {
  color: var(--yellow);
}

/* ============ 列表 ============ */
.feature-list {
  list-style: none;
  display: grid;
  gap: 14px;
}

.feature-list li {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  color: var(--text-soft);
}

.feature-list li .dot {
  flex: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--yellow-dim);
  color: var(--yellow);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 800;
  margin-top: 3px;
}

/* ============ FAQ ============ */
.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-card);
  margin-bottom: 14px;
  overflow: hidden;
}

.faq-item summary {
  cursor: pointer;
  padding: 20px 24px;
  font-weight: 700;
  font-size: 16.5px;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: color 0.2s;
}

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

.faq-item summary:hover { color: var(--yellow); }

.faq-item summary::after {
  content: "+";
  font-size: 22px;
  color: var(--yellow);
  font-weight: 400;
  transition: transform 0.2s;
}

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

.faq-item .faq-body {
  padding: 0 24px 22px;
  color: var(--text-muted);
  font-size: 15.5px;
}

/* ============ 頁尾 ============ */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 80px;
  padding: 48px 0 40px;
  text-align: center;
}

.site-footer .brand {
  justify-content: center;
}

.site-footer .foot-links {
  margin: 20px 0 14px;
  display: flex;
  justify-content: center;
  gap: 22px;
  flex-wrap: wrap;
}

.site-footer .foot-links a {
  color: var(--text-muted);
  font-size: 14px;
}

.site-footer .foot-links a:hover { color: var(--yellow); }

.site-footer .disclaimer {
  color: var(--text-faint);
  font-size: 12.5px;
  max-width: 720px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ============ 響應式 ============ */
@media (max-width: 900px) {
  .grid-3 { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }

  .nav-links {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: rgba(10, 13, 20, 0.98);
    flex-direction: column;
    align-items: stretch;
    padding: 16px 24px 24px;
    gap: 4px;
    border-bottom: 1px solid var(--border);
    display: none;
  }

  .nav-links.open { display: flex; }

  .nav-links a { padding: 13px 10px; font-size: 16px; }

  .nav-toggle { display: flex; }
}

@media (max-width: 560px) {
  .container { padding: 0 18px; }
  .hero { padding: 48px 0 40px; }
  .pred-hero-card { padding: 28px 20px; }
  .stat { min-width: 100%; }
}