/* ===========================
   SchedulAI - Common Styles
   Light Theme System
=========================== */

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

:root {
  /* Brand Colors */
  --primary: #4f6ef7;
  --primary-dark: #3a56e8;
  --primary-light: #e8edfe;
  --accent: #7c5cfc;
  --accent-light: #ede9fe;

  /* Light Theme Backgrounds */
  --bg-base: #f8faff;
  --bg-white: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f4f6fd;
  --bg-section-alt: #f1f4fe;
  --bg-subtle: #f8f9fc;

  /* Text */
  --text-primary: #0f1c3f;
  --text-secondary: #4a5578;
  --text-muted: #8693b5;
  --text-inverse: #ffffff;

  /* Borders */
  --border-color: #e2e8f4;
  --border-light: #edf0f8;

  /* Shadows */
  --shadow-sm: 0 1px 4px rgba(79, 110, 247, 0.07);
  --shadow-md: 0 4px 16px rgba(79, 110, 247, 0.10);
  --shadow-lg: 0 8px 32px rgba(79, 110, 247, 0.13);
  --shadow-card: 0 2px 12px rgba(15, 28, 63, 0.07);

  /* Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Typography */
  --font-sans: 'Pretendard', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', monospace;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s ease;

  /* Status Colors */
  --success: #22c55e;
  --success-light: #dcfce7;
  --warning: #f59e0b;
  --warning-light: #fef3c7;
  --error: #ef4444;
  --error-light: #fee2e2;
  --info: #3b82f6;
  --info-light: #dbeafe;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.25;
  font-weight: 700;
  color: var(--text-primary);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); }
h3 { font-size: clamp(1.1rem, 2vw, 1.4rem); }

p {
  color: var(--text-secondary);
  line-height: 1.7;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--primary-dark); }

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

ul, ol { list-style: none; }

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: var(--font-sans);
}

input, textarea, select {
  font-family: var(--font-sans);
  outline: none;
}

/* ===== Navigation ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: 64px;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(16px, 4vw, 48px);
  box-shadow: 0 1px 8px rgba(79,110,247,0.06);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.nav-logo-icon {
  width: 34px;
  height: 34px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 9px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
}

.nav-logo-text {
  font-size: 1.2rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  text-decoration: none;
}
.nav-link:hover {
  color: var(--primary);
  background: var(--primary-light);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-normal);
  white-space: nowrap;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  box-shadow: 0 4px 14px rgba(79,110,247,0.3);
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(79,110,247,0.4);
  color: #fff;
}

.btn-outline {
  border: 1.5px solid var(--border-color);
  color: var(--text-secondary);
  background: var(--bg-white);
}
.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}

.btn-ghost {
  color: var(--text-secondary);
  background: transparent;
  padding: 8px 14px;
}
.btn-ghost:hover {
  color: var(--primary);
  background: var(--primary-light);
}

.btn-sm {
  padding: 7px 16px;
  font-size: 0.82rem;
}

.btn-lg {
  padding: 14px 32px;
  font-size: 1rem;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

/* Hamburger (mobile) */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}
.nav-hamburger span {
  width: 22px;
  height: 2px;
  background: var(--text-secondary);
  border-radius: 2px;
  transition: all var(--transition-normal);
}

/* ===== Sections ===== */
.section {
  padding: clamp(60px, 8vw, 100px) clamp(16px, 4vw, 48px);
}

.section-alt {
  background: var(--bg-section-alt);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.2;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 580px;
  line-height: 1.7;
  margin-bottom: 48px;
}

/* ===== Cards ===== */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-card);
  transition: all var(--transition-normal);
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: var(--border-light);
}

/* ===== Badge ===== */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
}

.badge-success { background: var(--success-light); color: #166534; }
.badge-warning { background: var(--warning-light); color: #92400e; }
.badge-error { background: var(--error-light); color: #991b1b; }
.badge-info { background: var(--info-light); color: #1e40af; }
.badge-primary { background: var(--primary-light); color: var(--primary-dark); }

/* ===== Footer ===== */
.footer {
  background: #fff;
  border-top: 1px solid var(--border-light);
  padding: 48px clamp(16px,4vw,48px) 32px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 1fr);
  gap: 40px;
}

.footer-brand p {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-top: 12px;
  line-height: 1.6;
}

.footer-col h4 {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 14px;
}

.footer-col ul li {
  margin-bottom: 8px;
}

.footer-col ul li a {
  font-size: 0.88rem;
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-col ul li a:hover {
  color: var(--primary);
}

.footer-bottom {
  max-width: 1200px;
  margin: 32px auto 0;
  padding-top: 24px;
  border-top: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.83rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 8px;
}

/* ===== Utility ===== */
.text-center { text-align: center; }
.text-left { text-align: left; }

.mt-4 { margin-top: 16px; }
.mt-6 { margin-top: 24px; }
.mt-8 { margin-top: 32px; }

.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.gap-4 { gap: 16px; }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border-width: 0;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .footer-inner {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-menu { display: none; }
  .nav-hamburger { display: flex; }

  .nav-menu.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 64px;
    left: 0; right: 0;
    background: #fff;
    padding: 16px;
    border-bottom: 1px solid var(--border-light);
    box-shadow: var(--shadow-md);
    gap: 4px;
  }

  .nav-actions .btn-outline { display: none; }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-section-alt); }
::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ===== Focus Visible ===== */
*:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 3px;
  border-radius: 4px;
}