/* ==========================================================================
   WITH AI (위드AI) DESIGN SYSTEM - Core Tokens & Stylesheet
   Version: 1.0.0
   Brand: 위드AI | AI 교육 & AX 컨설팅 전문 기업
   Slogan: "AI와 함께, 더 나은 일과 비즈니스를 만듭니다."
   ========================================================================== */

/* --- Font Imports (IBM Plex Sans KR, IBM Plex Sans, IBM Plex Mono) --- */

/* --- Root Variables: Light Mode (Default) --- */
:root {
  /* Color - Brand Core Monochrome (Derived from With AI Logo) */
  --color-obsidian-950: #07080a;
  --color-obsidian-900: #0e1015;
  --color-obsidian-800: #181a22;
  --color-obsidian-700: #242834;
  --color-slate-600: #475569;
  --color-slate-500: #64748b;
  --color-slate-400: #94a3b8; /* Logo bracket gray tone */
  --color-slate-300: #cbd5e1;
  --color-slate-200: #e2e8f0;
  --color-slate-100: #f1f5f9;
  --color-slate-50: #f8fafc;
  --color-white: #ffffff;

  /* Color - Tech AI Electric Blue & Accents */
  --color-ai-blue-50: #eff6ff;
  --color-ai-blue-100: #dbeafe;
  --color-ai-blue-200: #bfdbfe;
  --color-ai-blue-400: #60a5fa;
  --color-ai-blue-500: #3b82f6;
  --color-ai-blue-600: #1d4ed8;
  --color-ai-electric: #0062ff;
  --color-ai-glow: rgba(0, 98, 255, 0.28);

  /* Color - AX Transformation Violet */
  --color-ax-violet-50: #eef2ff;
  --color-ax-violet-100: #e0e7ff;
  --color-ax-violet-400: #818cf8;
  --color-ax-violet-500: #6366f1;
  --color-ax-violet-700: #4338ca;
  --color-ax-glow: rgba(99, 102, 241, 0.25);

  /* Color - Cyber Cyan Highlight */
  --color-cyan-400: #22d3ee;
  --color-cyan-500: #06b6d4;

  /* Semantics */
  --color-success: #10b981;
  --color-success-bg: #ecfdf5;
  --color-warning: #f59e0b;
  --color-warning-bg: #fffbeb;
  --color-error: #ef4444;
  --color-error-bg: #fef2f2;
  --color-info: #0ea5e9;
  --color-info-bg: #f0f9ff;

  /* Surface & Theme Mapping - Light Mode */
  --bg-canvas: #ffffff;
  --bg-surface-primary: #ffffff;
  --bg-surface-secondary: #f8fafc;
  --bg-surface-tertiary: #f1f5f9;
  --bg-surface: #ffffff;
  --dropdown-bg: #ffffff;
  --dropdown-border: #e2e8f0;
  --dropdown-shadow: 0 16px 36px -4px rgba(14, 16, 21, 0.12), 0 0 0 1px rgba(0, 0, 0, 0.04);
  --bg-glass: rgba(255, 255, 255, 0.85);
  --bg-glass-border: rgba(226, 232, 240, 0.9);

  --border-subtle: #e2e8f0;
  --border-strong: #cbd5e1;
  --border-focus: var(--color-ai-electric);

  --text-primary: #0e1015;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-inverse: #ffffff;

  --bracket-color: #64748b;
  --logo-text-color: #0e1015;
  --logo-ai-gradient: linear-gradient(135deg, #181a22 0%, #64748b 100%);

  /* Typography - IBM Plex Family */
  --font-sans: "IBM Plex Sans KR", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-brand-en: "IBM Plex Sans", sans-serif;
  --font-code: "IBM Plex Mono", monospace;

  /* Shadows */
  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 2px 4px -1px rgba(0, 0, 0, 0.06), 0 1px 2px -1px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 12px -2px rgba(0, 0, 0, 0.08), 0 2px 6px -2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 12px 24px -4px rgba(14, 16, 21, 0.1), 0 4px 8px -2px rgba(14, 16, 21, 0.04);
  --shadow-xl: 0 24px 36px -8px rgba(14, 16, 21, 0.14), 0 8px 16px -4px rgba(14, 16, 21, 0.06);
  --shadow-glow: 0 0 24px 0 var(--color-ai-glow);
  --shadow-card-hover: 0 16px 32px -4px rgba(0, 98, 255, 0.12), 0 4px 12px -2px rgba(0, 0, 0, 0.05);

  /* Radius */
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --radius-2xl: 32px;
  --radius-full: 9999px;

  /* Transitions */
  --ease-spring: cubic-bezier(0.175, 0.885, 0.32, 1.275);
  --ease-smooth: cubic-bezier(0.16, 1, 0.3, 1);
  --transition-fast: 150ms var(--ease-smooth);
  --transition-base: 250ms var(--ease-smooth);
  --transition-slow: 400ms var(--ease-smooth);
}

/* --- Dark Mode Overrides --- */
[data-theme="dark"] {
  --bg-canvas: #07080a;
  --bg-surface-primary: #0e1015;
  --bg-surface-secondary: #141720;
  --bg-surface-tertiary: #1b1f2b;
  --bg-surface: #0e1015;
  --dropdown-bg: #141720;
  --dropdown-border: #2e3547;
  --dropdown-shadow: 0 20px 44px -4px rgba(0, 0, 0, 0.75), 0 0 0 1px rgba(255, 255, 255, 0.08);
  --bg-glass: rgba(14, 16, 21, 0.8);
  --bg-glass-border: rgba(255, 255, 255, 0.08);

  --border-subtle: #242834;
  --border-strong: #373e50;
  --border-focus: #38bdf8;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-inverse: #0e1015;

  --bracket-color: #94a3b8;
  --logo-text-color: #ffffff;
  --logo-ai-gradient: linear-gradient(135deg, #ffffff 0%, #94a3b8 100%);

  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
  --shadow-sm: 0 2px 6px 0 rgba(0, 0, 0, 0.5);
  --shadow-md: 0 6px 16px 0 rgba(0, 0, 0, 0.6);
  --shadow-lg: 0 14px 28px -4px rgba(0, 0, 0, 0.7);
  --shadow-xl: 0 24px 44px -8px rgba(0, 0, 0, 0.85);
  --shadow-glow: 0 0 30px 2px rgba(0, 98, 255, 0.45);
  --shadow-card-hover: 0 16px 36px -4px rgba(0, 98, 255, 0.25), 0 0 1px 1px rgba(0, 98, 255, 0.35);
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  -webkit-text-size-adjust: 100%;
  word-break: keep-all;
  overflow-wrap: break-word;
  scroll-behavior: smooth;
  transition: background-color var(--transition-slow), color var(--transition-slow);
}

body {
  min-height: 100vh;
  overflow-x: hidden;
  word-break: keep-all;
  overflow-wrap: break-word;
  background-color: var(--bg-canvas);
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

button, input, select, textarea {
  font: inherit;
}

/* --- Typography Utilities --- */
.font-sans { font-family: var(--font-sans); }
.font-brand { font-family: var(--font-brand-en); }
.font-code { font-family: var(--font-code); }

.display-2xl {
  font-size: clamp(1.85rem, 5.5vw, 4rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.035em;
}

.display-xl {
  font-size: clamp(1.6rem, 4.5vw, 3rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.03em;
}

.heading-1 {
  font-size: clamp(1.35rem, 3.5vw, 2.25rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.025em;
}

.heading-2 {
  font-size: clamp(1.2rem, 2.8vw, 1.75rem);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
}

.heading-3 {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: -0.015em;
}

.heading-4 {
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.45;
  letter-spacing: -0.01em;
}

.body-lg {
  font-size: 1.125rem;
  line-height: 1.7;
  letter-spacing: -0.01em;
}

.body-md {
  font-size: 1rem;
  line-height: 1.65;
  letter-spacing: -0.005em;
}

.body-sm {
  font-size: 0.875rem;
  line-height: 1.55;
}

.caption {
  font-size: 0.75rem;
  line-height: 1.4;
  letter-spacing: 0.02em;
}

/* Gradient Text */
.gradient-text-ai {
  background: linear-gradient(135deg, var(--color-ai-electric) 0%, #38bdf8 50%, var(--color-ax-violet-500) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gradient-text-monochrome {
  background: linear-gradient(180deg, var(--text-primary) 0%, var(--text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* --- Brand Signature Bracket [ ] Metaphor --- */
.brand-bracket-wrapper {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-brand-en);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.brand-logo .brand-bracket-wrapper,
.nav-logo-link .brand-bracket-wrapper {
  font-size: clamp(1.45rem, 3.2vw, 1.75rem);
  letter-spacing: -0.03em;
  font-weight: 800;
  line-height: 1;
}

.brand-logo .brand-bracket,
.nav-logo-link .brand-bracket {
  font-weight: 500;
}

.brand-bracket {
  color: var(--bracket-color);
  font-weight: 400;
  transition: color var(--transition-fast), transform var(--transition-fast);
  user-select: none;
}

.brand-bracket-left {
  margin-right: 0.15em;
}

.brand-bracket-right {
  margin-left: 0.15em;
}

.brand-badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.8125rem;
  font-weight: 600;
  background: var(--bg-surface-secondary);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  box-shadow: var(--shadow-xs);
  transition: all var(--transition-fast);
}

.brand-badge-pill:hover {
  border-color: var(--color-ai-electric);
  color: var(--color-ai-electric);
}

.brand-badge-pill .bracket-symbol {
  color: var(--color-ai-electric);
  font-weight: 700;
}