/* ============================================
   DeepSeek 下载页 - 样式表
   参考钉钉风格方向 | 稳重专业 | 蓝灰调
   ============================================ */

:root {
  --brand:       oklch(0.55 0.18 250);
  --brand-hover: oklch(0.46 0.17 250);
  --brand-light: oklch(0.94 0.03 250);
  --bg:          oklch(0.985 0.002 260);
  --surface:     oklch(1 0 0);
  --ink:         oklch(0.12 0.01 265);
  --ink-secondary: oklch(0.40 0.01 265);
  --ink-muted:   oklch(0.58 0.01 265);
  --border:      oklch(0.88 0.005 260);
  --border-light: oklch(0.93 0.003 260);

  --font: "PingFang SC","Microsoft YaHei","Hiragino Sans GB",system-ui,-apple-system,sans-serif;
  --mono: "SF Mono","Cascadia Code","Consolas",monospace;
  --w: 1040px;
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:var(--font);font-size:0.9375rem;line-height:1.65;
  color:var(--ink);background:var(--bg);-webkit-font-smoothing:antialiased;
}
a{color:var(--brand);text-decoration:none}
a:hover{color:var(--brand-hover)}
.wrap{max-width:var(--w);margin:0 auto;padding:0 28px}

/* ====== NAV ====== */
.navbar{
  position:sticky;top:0;z-index:100;
  background:oklch(1 0 0 / 0.92);backdrop-filter:blur(8px);
  border-bottom:1px solid var(--border);
}
.navbar .wrap{
  display:flex;align-items:center;justify-content:space-between;height:56px;
}
.nav-logo{
  display:flex;align-items:center;gap:10px;
  font-size:1.1rem;font-weight:700;color:var(--ink);
}
.nav-logo svg{width:28px;height:28px;flex-shrink:0}
.nav-links{display:flex;gap:28px}
.nav-links a{
  font-size:0.875rem;font-weight:500;color:var(--ink-secondary);padding:4px 0;
}
.nav-links a:hover,.nav-links a.active{color:var(--brand)}

/* ====== HERO ====== */
.hero{
  padding:72px 0 56px;background:var(--surface);
  border-bottom:1px solid var(--border);
}
.hero-inner{
  display:grid;grid-template-columns:1fr 320px;
  gap:48px;align-items:center;
}
.hero-text h1{
  font-size:2rem;font-weight:800;letter-spacing:-0.02em;
  margin-bottom:12px;
}
.hero-text p{
  color:var(--ink-secondary);font-size:1rem;max-width:440px;line-height:1.7;
}
.hero-visual{
  aspect-ratio:1;border-radius:16px;
  background:linear-gradient(135deg,var(--brand-light),oklch(0.97 0.04 240));
  display:flex;align-items:center;justify-content:center;
  font-size:5rem;
}

/* ====== PLATFORM TABS ====== */
.tabs-bar{
  padding:28px 0 0;border-bottom:1px solid var(--border);background:var(--surface);
}
.tabs{
  display:flex;gap:0;
}
.tab{
  padding:12px 28px;font-size:0.9rem;font-weight:600;
  color:var(--ink-secondary);cursor:pointer;border:none;
  background:none;font-family:inherit;
  border-bottom:2.5px solid transparent;
  transition:color 0.2s,border-color 0.2s;
  margin-bottom:-1px;
}
.tab:hover{color:var(--brand)}
.tab.active{color:var(--brand);border-bottom-color:var(--brand)}

/* ====== DOWNLOAD ROWS ====== */
.dl-content{padding:40px 0 64px}

.dl-platform-section{margin-bottom:48px}
.dl-platform-section:last-child{margin-bottom:0}

.dl-platform-header{
  display:flex;align-items:baseline;gap:16px;margin-bottom:20px;
}
.dl-platform-header h2{font-size:1.15rem;font-weight:700}
.dl-platform-header .dl-platform-ver{font-size:0.85rem;color:var(--ink-muted)}

.dl-options{display:flex;flex-direction:column;gap:12px}

.dl-option{
  display:grid;grid-template-columns:1fr auto;
  align-items:center;gap:24px;
  padding:18px 24px;border-radius:10px;
  border:1.5px solid var(--border);background:var(--surface);
  transition:border-color 0.2s,box-shadow 0.2s;
}
.dl-option:hover{border-color:var(--brand);box-shadow:0 2px 12px oklch(0 0 0 / 0.04)}
.dl-option--primary{border-color:var(--brand);background:var(--brand-light)}

.dl-option-info{display:flex;align-items:center;gap:16px}
.dl-option-os{
  font-size:0.95rem;font-weight:600;color:var(--ink);
  min-width:80px;
}
.dl-option-desc{font-size:0.85rem;color:var(--ink-muted)}
.dl-option-tag{
  display:inline-block;padding:1px 8px;border-radius:3px;
  font-size:0.75rem;font-weight:500;
  background:var(--brand);color:#fff;
  margin-left:8px;
}

.dl-download-btn{
  display:inline-flex;align-items:center;gap:6px;
  padding:10px 24px;border-radius:6px;
  font-size:0.875rem;font-weight:600;font-family:inherit;
  border:none;cursor:pointer;white-space:nowrap;
  color:#fff;background:var(--brand);
  transition:background 0.2s;
  text-decoration:none;
}
.dl-download-btn:hover{background:var(--brand-hover);color:#fff;text-decoration:none}

/* ====== FEATURES TABLE ====== */
.features-section{
  padding:56px 0;background:var(--surface);
  border-top:1px solid var(--border);border-bottom:1px solid var(--border);
}
.features-section h2{font-size:1.25rem;font-weight:700;margin-bottom:28px}

.ft-table{width:100%;border-collapse:collapse;font-size:0.875rem}
.ft-table thead th{
  text-align:left;padding:14px 20px;
  font-weight:600;font-size:0.8rem;color:var(--ink-muted);
  text-transform:uppercase;letter-spacing:0.04em;
  border-bottom:2px solid var(--border);
  background:oklch(0.98 0.003 260);
}
.ft-table thead th:first-child{border-radius:8px 0 0 0}
.ft-table thead th:last-child{border-radius:0 8px 0 0}
.ft-table td{
  padding:14px 20px;border-bottom:1px solid var(--border-light);
  color:var(--ink-secondary);
}
.ft-table td:first-child{font-weight:500;color:var(--ink)}
.ft-table tr:hover td{background:oklch(0.985 0.003 260)}
.ft-table .ft-yes{color:oklch(0.55 0.14 160);font-weight:600}
.ft-table .ft-no{color:var(--ink-muted)}

/* ====== SYSTEM REQUIREMENTS ====== */
.req-section{padding:56px 0 40px}

.req-section h2{font-size:1.25rem;font-weight:700;margin-bottom:28px}
.req-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:20px}

.req-item{padding:20px;border-radius:10px;background:var(--surface);border:1px solid var(--border)}
.req-item-os{font-weight:700;font-size:0.95rem;margin-bottom:8px;color:var(--ink)}
.req-item-row{display:flex;justify-content:space-between;padding:4px 0;font-size:0.85rem}
.req-item-row span:first-child{color:var(--ink-muted)}
.req-item-row span:last-child{color:var(--ink-secondary);font-weight:500}

/* ====== FOOTER ====== */
.footer{
  padding:40px 0;border-top:1px solid var(--border);
  font-size:0.8125rem;color:var(--ink-muted);background:var(--surface);
}
.footer .wrap{display:flex;justify-content:space-between;flex-wrap:wrap;gap:16px}
.footer a{color:var(--ink-muted)}
.footer a:hover{color:var(--brand)}

/* ====== RESPONSIVE ====== */
@media(max-width:768px){
  .hero-inner{grid-template-columns:1fr}
  .hero-visual{display:none}
  .hero-text h1{font-size:1.5rem}
  .tabs{gap:0;overflow-x:auto}
  .tab{padding:10px 18px;font-size:0.85rem}
  .dl-option{grid-template-columns:1fr;gap:12px}
  .dl-option-info{flex-wrap:wrap}
  .ft-table{font-size:0.8rem}
  .ft-table th,.ft-table td{padding:10px 12px}
  .navbar .wrap{flex-wrap:wrap;height:auto;padding:12px 28px 8px}
  .nav-links{gap:16px;overflow-x:auto}
}
/* ... (keep existing styles above, add these below) ... */

/* dt/dd reset for req-grid */
.req-item dl{margin:0;padding:0}
.req-item dt,.req-item dd{display:inline;margin:0;padding:0}
.req-item .req-item-row{display:flex;justify-content:space-between;padding:4px 0;font-size:0.85rem}
.req-item .req-item-row dt{color:var(--ink-muted);font-weight:400}
.req-item .req-item-row dd{color:var(--ink-secondary);font-weight:500}

/* Focus-visible for accessibility */
:focus-visible{outline:2px solid var(--brand);outline-offset:2px;border-radius:3px}
.tab:focus-visible{outline-offset:-2px}

/* Screen-reader-only */
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);border:0}

/* Table caption */
table caption{font-size:0}