:root {
  /* Color Palette */
  --primary: #00ffcc;
  --primary-dark: #00cc99;
  --primary-hover: #00cca3;
  --primary-active: #00cc99;
  --primary-dim: rgba(0, 255, 204, 0.08);
  --primary-glow: rgba(0, 255, 204, 0.5);

  --bg-body: #050505;
  --bg-surface: #0a0a0c;
  --bg-header: rgba(5, 5, 5, 0.85);
  --bg-header-top: rgba(5, 5, 5, 0.6);
  --bg-header-scrolled: rgba(5, 5, 5, 0.95);
  --bg-drawer: #0a0a0c;
  --bg-section: #0a0a0c;
  --bg-card: #111114;
  --bg-card-hover: #16161a;
  --bg-panel: #16161a;
  --bg-input: #1a1a1e;
  --bg-modal: #0a0a0c;
  --bg-disabled: #222222;

  --text-main: #ffffff;
  --text-muted: #9ca3af;
  --text-dark: #4b5563;
  --text-inverse: #000000;

  --accent-kakao: #fee500; /* Kakao Yellow */
  --text-kakao: #191919;

  --border: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(0, 255, 204, 0.5);
  --tag-bg: rgba(255, 255, 255, 0.04);

  --radius-sharp: 0px; /* Sharp edges for engineering feel */
  --radius-soft: 2px; /* Minimal radius */
  --shadow-glow: 0 0 20px rgba(0, 255, 204, 0.15);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);

  /* Spacing & Sizes */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 40px;
  --spacing-xxl: 80px;
  --spacing-section: 120px;

  --w-container: 1240px;
  --h-header: 72px;

  --container-width: 1200px;
  --header-height: 70px;
  --radius-sm: 2px;
  --radius-md: 4px;
  --radius-lg: 8px;

  --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
  --shadow-md: 0 10px 30px -10px rgba(0, 0, 0, 0.7);
  --shadow-lg: 0 20px 50px -20px rgba(0, 0, 0, 0.8);

  --trans-fast: all 0.2s ease;
  --trans-base: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  --trans-smooth: all 0.5s cubic-bezier(0.215, 0.61, 0.355, 1);

  --font-sans:
    "Pretendard", -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --font-mono:
    "JetBrains Mono", SF Mono, Consolas, "Liberation Mono", Menlo, Courier,
    monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  outline: none;
}

html,
body {
  letter-spacing: -0.3px;
  -ms-overflow-style: none;
  scrollbar-width: none;
}

html::-webkit-scrollbar,
body::-webkit-scrollbar {
  display: none;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--bg-body);
  color: var(--text-main);
  font-family:
    "Pretendard",
    -apple-system,
    BlinkMacSystemFont,
    system-ui,
    sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

ul,
ol {
  list-style: none;
}

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

button,
input,
textarea {
  border: none;
  background: none;
  font-family: inherit;
}

select {
  font-family: inherit;
  font-size: inherit;
  background: none;
  border: none;
  appearance: none;
  border-radius: 0;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-main);
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4.5rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
}

h3 {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

p {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

img,
svg,
video {
  display: block;
  max-width: 100%;
  height: auto;
}

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
}

.section-padding {
  padding: 120px 0;
}

.text-center {
  text-align: center;
}

.text-primary {
  color: var(--primary);
}

.text-muted {
  color: var(--text-muted);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  gap: 8px;
}

.btn-primary {
  background-color: var(--primary);
  color: #000;
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-2px);
}

.btn-kakao {
  background: var(--accent-kakao);
  color: var(--text-kakao);
  border: 1px solid var(--accent-kakao);
}

.btn-kakao:hover {
  background: #eacb00;
  transform: translateY(-2px);
}

.btn-outline {
  border: 1px solid var(--border);
  color: var(--text-main);
}

.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.badge {
  display: inline-block;
  padding: 4px 12px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--primary);
  background: var(--primary-dim);
  border: 1px solid rgba(0, 255, 204, 0.2);
  border-radius: 100px;
  margin-bottom: 1rem;
}