/* gpt-korea · main.css · v0.1.0 */

:root {
  --bg-base: #050508;
  --bg-card: rgba(255, 255, 255, 0.04);
  --bg-card-hover: rgba(255, 255, 255, 0.08);
  --bg-elevated: rgba(255, 255, 255, 0.06);
  --border-subtle: rgba(255, 255, 255, 0.1);
  --border-strong: rgba(255, 255, 255, 0.2);

  --accent-coral: #ff6b35;
  --accent-coral-soft: rgba(255, 107, 53, 0.15);
  --accent-coral-border: rgba(255, 107, 53, 0.3);
  --accent-coral-glow: rgba(255, 107, 53, 0.4);

  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.72);
  --text-muted: rgba(255, 255, 255, 0.5);

  --success: #34d399;
  --warning: #fbbf24;
  --danger: #f87171;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-pill: 999px;

  --shadow-card: 0 8px 24px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 16px 40px rgba(255, 107, 53, 0.12);

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;
  --space-9: 96px;

  --font-sans:
    "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont,
    system-ui, Roboto, "Helvetica Neue", sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", Consolas, monospace;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  background: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  min-height: 100vh;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(
      ellipse at top,
      rgba(255, 107, 53, 0.04) 0%,
      transparent 50%
    ),
    repeating-linear-gradient(
      to right,
      rgba(255, 255, 255, 0.015) 0px,
      rgba(255, 255, 255, 0.015) 1px,
      transparent 1px,
      transparent 40px
    );
  pointer-events: none;
  z-index: 0;
}

main,
.site-header,
.site-footer {
  position: relative;
  z-index: 1;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.18s ease;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent-coral);
  outline-offset: 3px;
  border-radius: 4px;
}

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-4) var(--space-5);
  max-width: 1200px;
  margin: 0 auto;
  position: sticky;
  top: 0;
  background: rgba(5, 5, 8, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  z-index: 100;
}

.brand {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.brand-mark {
  color: var(--text-primary);
}
.brand-accent {
  color: var(--accent-coral);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.nav-link {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
}
.nav-link:hover {
  color: var(--text-primary);
}

.usage-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 4px 12px;
  background: var(--accent-coral-soft);
  border: 1px solid var(--accent-coral-border);
  color: var(--accent-coral);
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 600;
}
.usage-badge strong {
  font-weight: 700;
}

.hero {
  padding: var(--space-9) var(--space-5) var(--space-8);
  max-width: 1200px;
  margin: 0 auto;
  text-align: center;
}

.hero-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-5);
  max-width: 760px;
  margin: 0 auto;
}

.pill-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 6px 14px;
  background: var(--accent-coral-soft);
  border: 1px solid var(--accent-coral-border);
  color: var(--accent-coral);
  border-radius: var(--radius-pill);
  font-size: 13px;
  font-weight: 600;
}

.hero-title {
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin: 0;
}
.hero-title em {
  font-style: normal;
  color: var(--accent-coral);
  font-weight: 800;
}

.hero-sub {
  font-size: clamp(16px, 2vw, 18px);
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.65;
}

.hero-actions {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
  justify-content: center;
  margin-top: var(--space-2);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 16px;
  transition: all 0.2s ease;
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
}
.btn-primary {
  background: var(--accent-coral);
  color: #000;
}
.btn-primary:hover {
  filter: brightness(1.08);
  transform: translateY(-1px);
  box-shadow: 0 8px 24px var(--accent-coral-glow);
}
.btn-ghost {
  background: transparent;
  border-color: var(--border-strong);
  color: var(--text-primary);
}
.btn-ghost:hover {
  background: var(--bg-card-hover);
}

.section-title {
  font-size: clamp(24px, 4vw, 36px);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 var(--space-6);
  text-align: center;
}

.tools {
  padding: var(--space-7) var(--space-5);
  max-width: 1200px;
  margin: 0 auto;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-4);
}

.tool-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-5);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  transition: all 0.22s ease;
  position: relative;
  overflow: hidden;
}
.tool-card:hover:not(.tool-card-soon) {
  background: var(--bg-card-hover);
  border-color: var(--accent-coral-border);
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
}
.tool-card-soon {
  opacity: 0.55;
  cursor: not-allowed;
}

.tool-icon {
  font-size: 32px;
  line-height: 1;
}

.tool-title {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0;
}

.tool-desc {
  font-size: 14px;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.55;
  flex-grow: 1;
}

.tool-meta {
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 500;
}

.why {
  padding: var(--space-7) var(--space-5) var(--space-9);
  max-width: 1200px;
  margin: 0 auto;
}

.why-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-4);
}

.why-card {
  padding: var(--space-5);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
}
.why-card h3 {
  margin: 0 0 var(--space-2);
  font-size: 16px;
  font-weight: 700;
}
.why-card p {
  margin: 0;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.site-footer {
  border-top: 1px solid var(--border-subtle);
  padding: var(--space-6) var(--space-5);
  margin-top: var(--space-7);
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  align-items: center;
  text-align: center;
}
.footer-brand {
  margin: 0;
  font-size: 13px;
  color: var(--text-muted);
}
.footer-nav {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  justify-content: center;
}
.footer-nav a {
  font-size: 13px;
  color: var(--text-secondary);
}
.footer-nav a:hover {
  color: var(--accent-coral);
}

.tool-page {
  max-width: 760px;
  margin: 0 auto;
  padding: var(--space-7) var(--space-5);
}

.tool-page-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
}
.tool-page-header .tool-icon {
  font-size: 40px;
}
.tool-page-header h1 {
  font-size: clamp(24px, 4vw, 32px);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0;
}

.tool-page-sub {
  color: var(--text-secondary);
  font-size: 15px;
  margin: 0 0 var(--space-6);
}

.tool-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  padding: var(--space-5);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
}

.field-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: var(--space-2);
  color: var(--text-primary);
}
.field-hint {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: var(--space-1);
}

.input,
.textarea {
  width: 100%;
  padding: 12px 14px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 15px;
  font-family: inherit;
  transition: border-color 0.18s ease;
}
.input:focus,
.textarea:focus {
  outline: none;
  border-color: var(--accent-coral);
}
.textarea {
  resize: vertical;
  min-height: 120px;
  line-height: 1.55;
}

.file-drop {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-6);
  background: var(--bg-elevated);
  border: 2px dashed var(--border-strong);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.18s ease;
  text-align: center;
}
.file-drop:hover,
.file-drop.dragover {
  border-color: var(--accent-coral);
  background: var(--accent-coral-soft);
}
.file-drop input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}
.file-drop-icon {
  font-size: 32px;
}
.file-drop-text {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: var(--space-2);
}

.result-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-5);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  margin-top: var(--space-5);
}
.result-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: var(--text-muted);
}
.result-body {
  white-space: pre-wrap;
  font-size: 15px;
  line-height: 1.7;
}

.btn-copy {
  font-size: 13px;
  padding: 6px 12px;
  background: var(--bg-card-hover);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  cursor: pointer;
}
.btn-copy:hover {
  border-color: var(--accent-coral);
  color: var(--accent-coral);
}
.btn-copy.copied {
  color: var(--success);
  border-color: var(--success);
}

.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-5);
  color: var(--text-secondary);
}
.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--border-subtle);
  border-top-color: var(--accent-coral);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.error-msg {
  padding: var(--space-3) var(--space-4);
  background: rgba(248, 113, 113, 0.1);
  border: 1px solid rgba(248, 113, 113, 0.3);
  border-radius: var(--radius-md);
  color: var(--danger);
  font-size: 14px;
}

@media (max-width: 640px) {
  .site-header {
    padding: var(--space-3) var(--space-4);
  }
  .nav-link {
    display: none;
  }
  .hero {
    padding: var(--space-7) var(--space-4) var(--space-6);
  }
  .tools,
  .why {
    padding-left: var(--space-4);
    padding-right: var(--space-4);
  }
  .tool-page {
    padding: var(--space-5) var(--space-4);
  }
  .hero-actions {
    width: 100%;
    flex-direction: column;
  }
  .btn {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html {
    scroll-behavior: auto;
  }
}