/* ================================================================
   System Design Interview Guide — Modern Premium Theme
   Glassmorphism + Gradient accents + Clean minimal layout
   ================================================================ */

/* ── Color System ─────────────────────────────────────────────── */
:root {
  --sdi-gradient-primary: linear-gradient(135deg, #7c3aed 0%, #2563eb 50%, #06b6d4 100%);
  --sdi-gradient-warm: linear-gradient(135deg, #f97316 0%, #ec4899 100%);
  --sdi-gradient-cool: linear-gradient(135deg, #06b6d4 0%, #8b5cf6 100%);
  --sdi-gradient-surface: linear-gradient(180deg, rgba(124, 58, 237, 0.03) 0%, transparent 100%);

  --sdi-glass: rgba(255, 255, 255, 0.05);
  --sdi-glass-border: rgba(255, 255, 255, 0.08);
  --sdi-glass-hover: rgba(255, 255, 255, 0.08);

  --sdi-success: #10b981;
  --sdi-warning: #f59e0b;
  --sdi-danger: #ef4444;
  --sdi-info: #3b82f6;

  --sdi-radius: 12px;
  --sdi-radius-lg: 16px;
  --sdi-radius-xl: 24px;
}

/* ── Dark Scheme ──────────────────────────────────────────────── */
[data-md-color-scheme="slate"] {
  --md-default-bg-color: #0c0a1d;
  --md-default-fg-color: #e8e6f0;
  --md-default-fg-color--light: #a5a0c0;
  --md-default-fg-color--lighter: #6e6990;
  --md-default-fg-color--lightest: #2a2545;
  --md-code-bg-color: #150f2e;
  --md-code-fg-color: #d4d0e8;
  --md-code-hl-color: rgba(124, 58, 237, 0.12);
  --md-typeset-a-color: #a78bfa;
  --md-footer-bg-color: #080618;
  --md-footer-bg-color--dark: #050412;
  --md-accent-fg-color: #22d3ee;
}

/* ── Light Scheme ─────────────────────────────────────────────── */
[data-md-color-scheme="default"] {
  --md-default-bg-color: #faf9ff;
  --md-code-bg-color: #f0eef8;
  --md-typeset-a-color: #6d28d9;
  --md-accent-fg-color: #0891b2;
}

/* ── Header ───────────────────────────────────────────────────── */
[data-md-color-scheme="slate"] .md-header {
  background: rgba(12, 10, 29, 0.85) !important;
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid rgba(124, 58, 237, 0.15);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

[data-md-color-scheme="default"] .md-header {
  background: rgba(250, 249, 255, 0.92) !important;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
  color: #1e1b4b;
}

[data-md-color-scheme="default"] .md-header .md-header__title,
[data-md-color-scheme="default"] .md-header .md-header__topic {
  color: #1e1b4b;
}

[data-md-color-scheme="default"] .md-header .md-header__button {
  color: #1e1b4b;
}

[data-md-color-scheme="default"] .md-header .md-search__icon,
[data-md-color-scheme="default"] .md-header .md-icon {
  color: #312e81;
}

[data-md-color-scheme="default"] .md-tabs {
  background: rgba(250, 249, 255, 0.95);
  border-bottom: 1px solid rgba(0, 0, 0, 0.04);
}

[data-md-color-scheme="default"] .md-tabs__link {
  color: #4A5568;
}

[data-md-color-scheme="default"] .md-tabs__link--active,
[data-md-color-scheme="default"] .md-tabs__link:hover {
  color: #1e1b4b;
}

.md-header__title {
  font-weight: 700;
  letter-spacing: -0.02em;
}

/* ── Sidebar ──────────────────────────────────────────────────── */
[data-md-color-scheme="slate"] .md-sidebar {
  background: rgba(12, 10, 29, 0.6);
  backdrop-filter: blur(12px);
  border-right: 1px solid rgba(124, 58, 237, 0.08);
}

.md-nav__link {
  font-size: 0.78rem;
  border-radius: 8px;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  padding: 0.35rem 0.6rem;
  margin: 1px 0;
}

.md-nav__link:hover {
  color: var(--md-accent-fg-color) !important;
  transform: translateX(2px);
}

[data-md-color-scheme="slate"] .md-nav__link:hover {
  background: var(--sdi-glass-hover);
}

[data-md-color-scheme="default"] .md-nav__link:hover {
  background: rgba(109, 40, 217, 0.06);
}

.md-nav__link--active {
  font-weight: 600;
  color: var(--md-accent-fg-color) !important;
  border-left: 2px solid var(--md-accent-fg-color);
}

[data-md-color-scheme="slate"] .md-nav__link--active {
  background: rgba(34, 211, 238, 0.08);
}

[data-md-color-scheme="default"] .md-nav__link--active {
  background: rgba(109, 40, 217, 0.06);
}

.md-nav__item--nested > .md-nav__link {
  font-weight: 700;
  text-transform: uppercase;
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  color: var(--md-default-fg-color--light);
  padding-top: 0.8rem;
}

/* ── Typography ───────────────────────────────────────────────── */
.md-typeset {
  font-size: 0.84rem;
  line-height: 1.85;
  letter-spacing: 0.005em;
}

.md-typeset h1 {
  font-weight: 800;
  font-size: 2.2em;
  letter-spacing: -0.04em;
  line-height: 1.2;
  margin-bottom: 0.6em;
}

[data-md-color-scheme="slate"] .md-typeset h1 {
  background: var(--sdi-gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-md-color-scheme="default"] .md-typeset h1 {
  color: #1e1b4b;
}

.md-typeset h2 {
  font-weight: 700;
  font-size: 1.5em;
  margin-top: 3em;
  margin-bottom: 0.8em;
  padding-bottom: 0.5em;
  letter-spacing: -0.02em;
  position: relative;
}

[data-md-color-scheme="slate"] .md-typeset h2 {
  border-bottom: 1px solid rgba(124, 58, 237, 0.15);
}

.md-typeset h2::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 60px;
  height: 2px;
  background: var(--sdi-gradient-primary);
  border-radius: 2px;
}

.md-typeset h3 {
  font-weight: 600;
  font-size: 1.15em;
  margin-top: 2.2em;
  letter-spacing: -0.01em;
}

[data-md-color-scheme="slate"] .md-typeset h3 {
  color: var(--md-accent-fg-color);
}

[data-md-color-scheme="default"] .md-typeset h3 {
  color: #4338ca;
}

[data-md-color-scheme="default"] .md-typeset h2 {
  color: #1e1b4b;
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.md-typeset h4 {
  font-weight: 600;
  font-size: 1em;
  margin-top: 1.6em;
  color: var(--md-default-fg-color--light);
}

/* ── Content Width ────────────────────────────────────────────── */
.md-grid {
  max-width: 1440px;
}

/* ── Tables — Glass Card Style ────────────────────────────────── */
.md-typeset table:not([class]) {
  border-collapse: separate;
  border-spacing: 0;
  width: 100%;
  font-size: 0.78rem;
  display: table;
  border-radius: var(--sdi-radius);
  overflow: hidden;
}

[data-md-color-scheme="slate"] .md-typeset table:not([class]) {
  background: var(--sdi-glass);
  border: 1px solid var(--sdi-glass-border);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.2),
              inset 0 1px 0 rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(8px);
}

.md-typeset table:not([class]) th {
  font-weight: 700;
  text-transform: uppercase;
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-align: left;
  padding: 1rem 1.2rem;
}

[data-md-color-scheme="slate"] .md-typeset table:not([class]) th {
  background: rgba(124, 58, 237, 0.08);
  color: #a78bfa;
  border-bottom: 1px solid rgba(124, 58, 237, 0.15);
}

.md-typeset table:not([class]) td {
  padding: 0.85rem 1.2rem;
  line-height: 1.65;
  transition: background 0.2s ease;
}

[data-md-color-scheme="slate"] .md-typeset table:not([class]) td {
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.md-typeset table:not([class]) tr:last-child td {
  border-bottom: none;
}

.md-typeset table:not([class]) tbody tr:hover td {
  background: rgba(124, 58, 237, 0.04);
}

/* ── Code Blocks — Glass Style ────────────────────────────────── */
.md-typeset pre {
  border-radius: var(--sdi-radius);
  overflow: hidden;
}

[data-md-color-scheme="slate"] .md-typeset pre {
  background: rgba(21, 15, 46, 0.8) !important;
  border: 1px solid rgba(124, 58, 237, 0.1);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3),
              inset 0 1px 0 rgba(255, 255, 255, 0.03);
  backdrop-filter: blur(8px);
}

.md-typeset code {
  border-radius: 6px;
  font-size: 0.85em;
}

[data-md-color-scheme="slate"] .md-typeset :not(pre) > code {
  background: rgba(124, 58, 237, 0.1);
  color: #c4b5fd;
  border: 1px solid rgba(124, 58, 237, 0.15);
  padding: 0.15em 0.45em;
}

/* ── Admonitions — Modern Card ────────────────────────────────── */
.md-typeset .admonition,
.md-typeset details {
  border-radius: var(--sdi-radius);
  border: none;
  font-size: 0.84rem;
  overflow: hidden;
}

[data-md-color-scheme="slate"] .md-typeset .admonition,
[data-md-color-scheme="slate"] .md-typeset details {
  background: var(--sdi-glass);
  border: 1px solid var(--sdi-glass-border);
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.15);
  backdrop-filter: blur(8px);
}

.md-typeset .admonition-title,
.md-typeset summary {
  font-weight: 600;
  letter-spacing: 0.01em;
  border-radius: var(--sdi-radius) var(--sdi-radius) 0 0;
}

/* Tip admonition accent */
[data-md-color-scheme="slate"] .md-typeset .admonition.tip,
[data-md-color-scheme="slate"] .md-typeset details.tip {
  border-left: 3px solid var(--sdi-success);
}

/* Warning admonition accent */
[data-md-color-scheme="slate"] .md-typeset .admonition.warning,
[data-md-color-scheme="slate"] .md-typeset details.warning {
  border-left: 3px solid var(--sdi-warning);
}

/* Note admonition accent */
[data-md-color-scheme="slate"] .md-typeset .admonition.note,
[data-md-color-scheme="slate"] .md-typeset details.note {
  border-left: 3px solid var(--sdi-info);
}

/* Custom interview admonition */
:root {
  --md-admonition-icon--interview: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 2H4c-1.1 0-2 .9-2 2v18l4-4h14c1.1 0 2-.9 2-2V4c0-1.1-.9-2-2-2m0 14H6l-2 2V4h16"/></svg>');
}
.md-typeset .admonition.interview,
.md-typeset details.interview {
  border-left: 3px solid var(--sdi-success);
}
.md-typeset .interview > .admonition-title,
.md-typeset .interview > summary {
  background-color: rgba(16, 185, 129, 0.08);
}
.md-typeset .interview > .admonition-title::before,
.md-typeset .interview > summary::before {
  background-color: var(--sdi-success);
  -webkit-mask-image: var(--md-admonition-icon--interview);
  mask-image: var(--md-admonition-icon--interview);
}

/* ── Mermaid Diagrams ─────────────────────────────────────────── */
.mermaid {
  max-width: 100%;
  margin: 2rem 0;
  padding: 2rem;
  border-radius: var(--sdi-radius-lg);
  overflow-x: auto;
}

[data-md-color-scheme="slate"] .mermaid {
  background: linear-gradient(145deg, rgba(21, 15, 46, 0.6) 0%, rgba(12, 10, 29, 0.8) 100%) !important;
  border: 1px solid rgba(124, 58, 237, 0.1);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  backdrop-filter: blur(12px);
}

.mermaid svg {
  max-width: 100%;
  height: auto;
  min-height: 200px;
}

[data-md-color-scheme="slate"] .mermaid text,
[data-md-color-scheme="slate"] .mermaid tspan,
[data-md-color-scheme="slate"] .mermaid span,
[data-md-color-scheme="slate"] .mermaid .label,
[data-md-color-scheme="slate"] .mermaid .edgeLabel span,
[data-md-color-scheme="slate"] .mermaid .edgeLabel p,
[data-md-color-scheme="slate"] .mermaid .messageText,
[data-md-color-scheme="slate"] .mermaid .loopText,
[data-md-color-scheme="slate"] .mermaid .noteText,
[data-md-color-scheme="slate"] .mermaid .actor text,
[data-md-color-scheme="slate"] .mermaid foreignObject div,
[data-md-color-scheme="slate"] .mermaid foreignObject span {
  fill: #ffffff !important;
  color: #ffffff !important;
  font-weight: 600 !important;
  font-family: 'Inter', sans-serif !important;
}

[data-md-color-scheme="slate"] .mermaid .edgeLabel {
  background-color: rgba(42, 37, 69, 0.9) !important;
  padding: 6px 10px !important;
  border-radius: 8px !important;
  border: 1px solid rgba(124, 58, 237, 0.2) !important;
}

[data-md-color-scheme="slate"] .mermaid .edgeLabel rect {
  fill: rgba(42, 37, 69, 0.9) !important;
  stroke: rgba(124, 58, 237, 0.2) !important;
}

[data-md-color-scheme="slate"] .mermaid line,
[data-md-color-scheme="slate"] .mermaid .messageLine0,
[data-md-color-scheme="slate"] .mermaid .messageLine1,
[data-md-color-scheme="slate"] .mermaid path.path,
[data-md-color-scheme="slate"] .mermaid .flowchart-link {
  stroke: #22d3ee !important;
  stroke-width: 2px !important;
}

[data-md-color-scheme="slate"] .mermaid marker path,
[data-md-color-scheme="slate"] .mermaid marker polygon {
  fill: #22d3ee !important;
}

[data-md-color-scheme="slate"] .mermaid .node rect,
[data-md-color-scheme="slate"] .mermaid .node polygon,
[data-md-color-scheme="slate"] .mermaid .node circle {
  fill: rgba(124, 58, 237, 0.12) !important;
  stroke: #a78bfa !important;
  stroke-width: 2px !important;
  rx: 10 !important;
  ry: 10 !important;
}

[data-md-color-scheme="slate"] .mermaid .cluster rect {
  fill: rgba(12, 10, 29, 0.5) !important;
  stroke: rgba(124, 58, 237, 0.15) !important;
  rx: 12 !important;
}

[data-md-color-scheme="slate"] .mermaid .cluster text {
  fill: #a78bfa !important;
  font-weight: 700 !important;
}

[data-md-color-scheme="slate"] .mermaid .actor {
  fill: rgba(124, 58, 237, 0.12) !important;
  stroke: #a78bfa !important;
}

[data-md-color-scheme="slate"] .mermaid .note {
  fill: rgba(245, 158, 11, 0.1) !important;
  stroke: #f59e0b !important;
}

[data-md-color-scheme="slate"] .mermaid .activation0,
[data-md-color-scheme="slate"] .mermaid .activation1,
[data-md-color-scheme="slate"] .mermaid .activation2 {
  fill: rgba(124, 58, 237, 0.15) !important;
  stroke: #a78bfa !important;
}

/* ── Blockquotes ──────────────────────────────────────────────── */
[data-md-color-scheme="slate"] .md-typeset blockquote {
  border-left: 3px solid #7c3aed;
  background: linear-gradient(135deg, rgba(124, 58, 237, 0.06) 0%, transparent 100%);
  border-radius: 0 var(--sdi-radius) var(--sdi-radius) 0;
  padding: 1rem 1.25rem;
  backdrop-filter: blur(4px);
}

/* ── Horizontal Rules ─────────────────────────────────────────── */
.md-typeset hr {
  border: none;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(124, 58, 237, 0.2), var(--md-accent-fg-color), rgba(124, 58, 237, 0.2), transparent);
  margin: 3.5rem 0;
  opacity: 0.6;
}

/* ── Links ────────────────────────────────────────────────────── */
.md-typeset a {
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.md-typeset a:hover {
  border-bottom-color: currentColor;
  opacity: 0.9;
}

/* ── Search — Glass ───────────────────────────────────────────── */
[data-md-color-scheme="slate"] .md-search__form {
  background: rgba(21, 15, 46, 0.7);
  border: 1px solid rgba(124, 58, 237, 0.15);
  border-radius: var(--sdi-radius);
  backdrop-filter: blur(12px);
}

[data-md-color-scheme="slate"] .md-search__input::placeholder {
  color: rgba(167, 139, 250, 0.5);
}

/* ── Footer ───────────────────────────────────────────────────── */
.md-footer {
  margin-top: 4em;
}

[data-md-color-scheme="slate"] .md-footer {
  border-top: 1px solid rgba(124, 58, 237, 0.1);
  background: rgba(8, 6, 24, 0.8) !important;
  backdrop-filter: blur(12px);
}

.md-footer__title {
  font-weight: 600;
}

.md-footer__direction {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  opacity: 0.6;
}

/* ── Scrollbar ────────────────────────────────────────────────── */
[data-md-color-scheme="slate"] ::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

[data-md-color-scheme="slate"] ::-webkit-scrollbar-track {
  background: transparent;
}

[data-md-color-scheme="slate"] ::-webkit-scrollbar-thumb {
  background: rgba(124, 58, 237, 0.3);
  border-radius: 3px;
}

[data-md-color-scheme="slate"] ::-webkit-scrollbar-thumb:hover {
  background: rgba(124, 58, 237, 0.5);
}

/* ── Page Animation ───────────────────────────────────────────── */
.md-content {
  animation: fadeInUp 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* ── Instant Loading Progress ─────────────────────────────────── */
.md-progress {
  background: var(--sdi-gradient-primary) !important;
}

/* ── Light mode — Tables ─────────────────────────────────────── */
[data-md-color-scheme="default"] .md-typeset table:not([class]) {
  border: 1px solid rgba(0, 0, 0, 0.08);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.04);
}

[data-md-color-scheme="default"] .md-typeset table:not([class]) th {
  background: rgba(99, 102, 241, 0.05);
  color: #4338ca;
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

[data-md-color-scheme="default"] .md-typeset table:not([class]) td {
  border-bottom: 1px solid rgba(0, 0, 0, 0.04);
}

[data-md-color-scheme="default"] .md-typeset table:not([class]) tbody tr:hover td {
  background: rgba(99, 102, 241, 0.03);
}

/* ── Light mode — Code ───────────────────────────────────────── */
[data-md-color-scheme="default"] .md-typeset pre {
  border: 1px solid rgba(0, 0, 0, 0.06);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.03);
}

[data-md-color-scheme="default"] .md-typeset :not(pre) > code {
  background: rgba(99, 102, 241, 0.06);
  color: #4338ca;
  border: 1px solid rgba(99, 102, 241, 0.1);
}

/* ── Light mode — Sidebar ────────────────────────────────────── */
[data-md-color-scheme="default"] .md-sidebar {
  border-right: 1px solid rgba(0, 0, 0, 0.04);
}

[data-md-color-scheme="default"] .md-nav__link--active {
  background: rgba(99, 102, 241, 0.06);
  border-left: 2px solid var(--md-accent-fg-color);
}

/* ── Light mode — Admonitions ────────────────────────────────── */
[data-md-color-scheme="default"] .md-typeset .admonition,
[data-md-color-scheme="default"] .md-typeset details {
  border: 1px solid rgba(0, 0, 0, 0.06);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.03);
}

/* ── Light mode — Search ─────────────────────────────────────── */
[data-md-color-scheme="default"] .md-search__form {
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: var(--sdi-radius);
}

/* ── Light mode — Footer ─────────────────────────────────────── */
[data-md-color-scheme="default"] .md-footer {
  border-top: 1px solid rgba(0, 0, 0, 0.06);
}

/* ── Light mode — h2 underline ───────────────────────────────── */
[data-md-color-scheme="default"] .md-typeset h2::after {
  background: linear-gradient(135deg, #4338ca, #0891b2);
}

/* ── Navigation Path (Breadcrumbs) ────────────────────────────── */
.md-path {
  font-size: 0.72rem;
  opacity: 0.7;
}

/* ── Responsive ───────────────────────────────────────────────── */
@media (max-width: 768px) {
  .md-typeset h1 {
    font-size: 1.8em;
  }

  .md-typeset table:not([class]) {
    font-size: 0.72rem;
  }

  .md-typeset table:not([class]) th,
  .md-typeset table:not([class]) td {
    padding: 0.6rem 0.8rem;
  }
}

/* ── Print ────────────────────────────────────────────────────── */
@media print {
  .md-typeset h1 {
    background: none;
    -webkit-text-fill-color: initial;
    color: #1e293b;
  }

  .md-typeset h2::after {
    display: none;
  }
}