/* ============================================================
   Y.DOG 商业级设计系统 (Enterprise & Consumer Security Spec)
   ============================================================
   高端、克制、严谨、深邃的数字安全视觉规范 (+2px 全端舒适排印)
   ============================================================ */

:root {
  /* Slate / Obsidian Neutral Palette */
  --ydog-bg: #ffffff;
  --ydog-bg-subtle: #f8fafc;
  --ydog-surface: #ffffff;
  --ydog-surface-subtle: #f1f5f9;
  --ydog-surface-hover: #f8fafc;

  /* Typography Colors */
  --ydog-text-primary: #0f172a;   /* Slate 900: Deep, authoritative obsidian */
  --ydog-text-secondary: #475569; /* Slate 600: Refined readable slate */
  --ydog-text-tertiary: #94a3b8;  /* Slate 400 */
  --ydog-text-inverse: #ffffff;

  /* Brand / Identity Blue (SaaS Enterprise Level) */
  --ydog-primary: #0052cc;
  --ydog-primary-hover: #0747a6;
  --ydog-primary-pressed: #003882;
  --ydog-primary-light: #e9f2ff;
  --ydog-primary-border: #b3d4ff;

  /* Status Colors */
  --ydog-success: #15803d;
  --ydog-success-light: #f0fdf4;
  --ydog-warning: #b45309;
  --ydog-warning-light: #fffbeb;
  --ydog-error: #dc2626;
  --ydog-error-light: #fef2f2;

  /* Hairlines & Borders */
  --ydog-border: #e2e8f0;         /* Slate 200: Crisp, subtle hairline */
  --ydog-border-strong: #cbd5e1;  /* Slate 300 */
  --ydog-border-subtle: #f1f5f9;  /* Slate 100 */

  /* Micro Shadows */
  --ydog-shadow-xs: 0 1px 2px 0 rgba(15, 23, 42, 0.05);
  --ydog-shadow-sm: 0 1px 3px 0 rgba(15, 23, 42, 0.08), 0 1px 2px -1px rgba(15, 23, 42, 0.08);
  --ydog-shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -2px rgba(15, 23, 42, 0.08);
  --ydog-btn-shadow: 0 1px 2px rgba(0, 82, 204, 0.2), inset 0 1px 0 rgba(255, 255, 255, 0.16);

  /* Layout */
  --ydog-header-height: 64px;
  --ydog-content-max: 1160px;
  --ydog-gutter: 24px;

  /* Native Hardware-Accelerated Font Stack (Zero FOUC lag) */
  --ydog-font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --ydog-font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
  :root {
    --ydog-bg: #0b0f19;
    --ydog-bg-subtle: #111827;
    --ydog-surface: #151d2e;
    --ydog-surface-subtle: #1f293d;
    --ydog-surface-hover: #1b253b;

    --ydog-text-primary: #f8fafc;
    --ydog-text-secondary: #cbd5e1;
    --ydog-text-tertiary: #64748b;

    --ydog-primary: #38bdf8;
    --ydog-primary-hover: #7dd3fc;
    --ydog-primary-light: #082f49;
    --ydog-primary-border: #0369a1;

    --ydog-border: #1e293b;
    --ydog-border-strong: #334155;
    --ydog-border-subtle: #111827;
  }
}

/* ---------- Base & Reset ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scrollbar-gutter: stable;
  font-size: 16px; /* 全局放大 2px，超清大屏与移动端黄金阅读基准 */
  background-color: var(--ydog-bg);
}

body {
  font-family: var(--ydog-font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--ydog-text-primary);
  background-color: var(--ydog-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

/* ---------- Containers & Grid ---------- */
.ydog-container {
  width: 100%;
  max-width: var(--ydog-content-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--ydog-gutter);
  padding-right: var(--ydog-gutter);
}

.ydog-main {
  flex: 1 0 auto;
  padding-top: 24px;
  padding-bottom: 64px;
}

/* ---------- Navigation Header (Minimalist & Pure Text) ---------- */
.ydog-header {
  height: var(--ydog-header-height);
  background: var(--ydog-bg);
  border-bottom: 1px solid var(--ydog-border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.ydog-header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.ydog-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 20px;
  letter-spacing: -0.02em;
  color: var(--ydog-text-primary);
}

.ydog-brand-logo {
  width: 32px;
  height: 32px;
  border-radius: 6px;
  display: block;
  flex-shrink: 0;
}

.ydog-brand-name {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.ydog-nav-list {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.ydog-nav-link {
  font-size: 16px;
  font-weight: 500;
  color: var(--ydog-text-secondary);
  transition: color 0.15s ease;
  padding: 8px 0;
  position: relative;
}

.ydog-nav-link:hover {
  color: var(--ydog-text-primary);
}

.ydog-nav-link.is-active {
  color: var(--ydog-primary);
  font-weight: 600;
}

.ydog-nav-link.is-active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--ydog-primary);
  border-radius: 2px;
}

/* Mobile Nav Toggle */
.ydog-menu-toggle {
  display: none;
  background: none;
  border: none;
  padding: 6px;
  color: var(--ydog-text-primary);
  cursor: pointer;
}

.ydog-mobile-menu {
  display: none;
  background: var(--ydog-surface);
  border-bottom: 1px solid var(--ydog-border);
  padding: 16px var(--ydog-gutter);
}

.ydog-mobile-menu.is-open {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

@media (max-width: 768px) {
  .ydog-nav-list { display: none; }
  .ydog-menu-toggle { display: block; }
}

/* ---------- Typography & Titles ---------- */
.ydog-title {
  font-size: clamp(32px, 5vw, 46px);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.03em;
  color: var(--ydog-text-primary);
}

.ydog-subtitle {
  font-size: 16px;
  color: var(--ydog-text-secondary);
  line-height: 1.6;
}

/* ---------- Buttons ---------- */
.ydog-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  font-size: 16px;
  border-radius: 8px;
  padding: 10px 22px;
  cursor: pointer;
  transition: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid transparent;
  white-space: nowrap;
  user-select: none;
}

.ydog-btn--primary {
  background-color: var(--ydog-primary);
  color: #ffffff !important;
  box-shadow: var(--ydog-btn-shadow);
}
.ydog-btn--primary:hover {
  background-color: var(--ydog-primary-hover);
  transform: translateY(-1px);
}
.ydog-btn--primary:active {
  background-color: var(--ydog-primary-pressed);
  transform: translateY(0);
}

.ydog-btn--secondary {
  background-color: var(--ydog-surface);
  color: var(--ydog-text-primary);
  border-color: var(--ydog-border);
  box-shadow: var(--ydog-shadow-xs);
}
.ydog-btn--secondary:hover {
  background-color: var(--ydog-surface-subtle);
  border-color: var(--ydog-border-strong);
  color: var(--ydog-text-primary);
}

.ydog-btn--ghost {
  background: transparent;
  color: var(--ydog-text-secondary);
}
.ydog-btn--ghost:hover {
  background-color: var(--ydog-surface-subtle);
  color: var(--ydog-text-primary);
}

.ydog-btn--lg {
  padding: 14px 28px;
  font-size: 17px;
  border-radius: 9px;
}

.ydog-btn--block {
  width: 100%;
}

/* ---------- Cards & Containers ---------- */
.ydog-card {
  background-color: var(--ydog-surface);
  border: 1px solid var(--ydog-border);
  border-radius: 12px;
  padding: 28px;
  box-shadow: var(--ydog-shadow-xs);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.ydog-card:hover {
  border-color: var(--ydog-border-strong);
  box-shadow: var(--ydog-shadow-sm);
}

/* ---------- Tags & Chips ---------- */
.ydog-tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  font-weight: 600;
  padding: 3px 9px;
  border-radius: 9999px;
  background-color: var(--ydog-surface-subtle);
  color: var(--ydog-text-secondary);
  border: 1px solid var(--ydog-border);
}

.ydog-tag--primary {
  background-color: var(--ydog-primary-light);
  color: var(--ydog-primary);
  border-color: var(--ydog-primary-border);
}

.ydog-tag--success {
  background-color: var(--ydog-success-light);
  color: var(--ydog-success);
  border-color: transparent;
}

.ydog-tag--warning {
  background-color: var(--ydog-warning-light);
  color: var(--ydog-warning);
  border-color: transparent;
}

.ydog-tag--error {
  background-color: var(--ydog-error-light);
  color: var(--ydog-error);
  border-color: transparent;
}

/* ---------- Minimalist Clean Single-Line Footer ---------- */
.ydog-footer {
  border-top: 1px solid var(--ydog-border);
  background-color: var(--ydog-bg);
  padding: 32px 0;
  margin-top: auto;
}

.ydog-footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.ydog-footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 700;
  color: var(--ydog-text-primary);
}

.ydog-footer-copy {
  font-size: 14px;
  color: var(--ydog-text-tertiary);
}