/* ==========================================================================
   CONVIVIUM — Design System & Core Stylesheet
   Themes: Parchment (Default), Scholar Dark, Athenian Obsidian, Modern Light
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Cardo:ital,wght@0,400;0,700;1,400&family=Cinzel:wght@400;600;700;900&family=Cormorant+Garamond:ital,wght@0,400;0,600;0,700;1,400;1,600&family=EB+Garamond:ital,wght@0,400;0,600;0,700;1,400&family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  /* Common Brand Colors */
  --color-gold: #c59b27;
  --color-gold-hover: #dfaf33;
  --color-terracotta: #b84a39;
  --color-lapis: #1f5f8b;
  --color-olive: #4a6b47;
  --color-amethyst: #6c4b7c;

  /* Typography Scale */
  --font-serif-cormorant: 'Cormorant Garamond', Georgia, 'Times New Roman', serif;
  --font-serif-garamond: 'EB Garamond', Georgia, serif;
  --font-serif-cardo: 'Cardo', 'Palatino Linotype', serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-title: 'Cinzel', 'Trajan Pro', Georgia, serif;
  --font-mono: 'JetBrains Mono', monospace;

  --user-font-family: var(--font-serif-cormorant);
  --user-font-size: 18px;
  --user-line-height: 1.7;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;

  /* Border Radius & Shadows */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 14px;
  --radius-pill: 9999px;

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.4s ease;

  /* Header & Navigation */
  --nav-height: 64px;
}

/* ==========================================================================
   THEME 1: PARCHMENT (Classical Manuscript / Warm Sepia)
   ========================================================================== */
[data-theme="parchment"] {
  --bg-primary: #fbf7ee;
  --bg-secondary: #f4edd9;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #ffffff;
  --bg-highlight: #fff2c4;
  --bg-highlight-border: #d4af37;
  --bg-active-row: #f5eed6;

  --text-primary: #2c251e;
  --text-secondary: #5e5246;
  --text-muted: #8b7d6f;
  --text-inverse: #ffffff;

  --border-subtle: #e6dcbe;
  --border-strong: #c8b992;
  --border-accent: #9e472a;

  --accent-primary: #8c2d19;
  --accent-secondary: #b27a18;
  --accent-surface: #f9efe0;

  --shadow-sm: 0 1px 3px rgba(60, 40, 20, 0.06);
  --shadow-md: 0 4px 12px rgba(60, 40, 20, 0.08);
  --shadow-lg: 0 12px 32px rgba(60, 40, 20, 0.12);

  --greek-color: #1a4a6b;
  --latin-color: #8c2d19;
}

/* ==========================================================================
   THEME 2: SCHOLAR DARK (Deep Velvet Study)
   ========================================================================== */
[data-theme="scholar-dark"] {
  --bg-primary: #14171d;
  --bg-secondary: #1b2029;
  --bg-surface: #222834;
  --bg-surface-elevated: #2a3242;
  --bg-highlight: #3b3524;
  --bg-highlight-border: #e5b842;
  --bg-active-row: #252e3e;

  --text-primary: #eaeef4;
  --text-secondary: #aab5c6;
  --text-muted: #748194;
  --text-inverse: #0d1117;

  --border-subtle: #2d3648;
  --border-strong: #414e66;
  --border-accent: #e5b842;

  --accent-primary: #e5b842;
  --accent-secondary: #4ea8de;
  --accent-surface: #2a2c26;

  --shadow-sm: 0 1px 4px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 6px 16px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 14px 40px rgba(0, 0, 0, 0.65);

  --greek-color: #64b5f6;
  --latin-color: #ff8a80;
}

/* ==========================================================================
   THEME 3: ATHENIAN OBSIDIAN (Pure Midnight & Gold)
   ========================================================================== */
[data-theme="athenian-obsidian"] {
  --bg-primary: #0a0a0c;
  --bg-secondary: #121216;
  --bg-surface: #18181e;
  --bg-surface-elevated: #22222b;
  --bg-highlight: #2e2612;
  --bg-highlight-border: #d4af37;
  --bg-active-row: #1c1c24;

  --text-primary: #f5f5f7;
  --text-secondary: #9e9ea7;
  --text-muted: #6b6b75;
  --text-inverse: #000000;

  --border-subtle: #272732;
  --border-strong: #3e3e50;
  --border-accent: #d4af37;

  --accent-primary: #d4af37;
  --accent-secondary: #48cae4;
  --accent-surface: #262214;

  --shadow-sm: 0 1px 4px rgba(0, 0, 0, 0.7);
  --shadow-md: 0 6px 20px rgba(0, 0, 0, 0.8);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.9);

  --greek-color: #48cae4;
  --latin-color: #e07a5f;
}

/* ==========================================================================
   THEME 4: MODERN LIGHT (Clean Editorial)
   ========================================================================== */
[data-theme="modern-light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #f1f5f9;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #ffffff;
  --bg-highlight: #fef3c7;
  --bg-highlight-border: #f59e0b;
  --bg-active-row: #f1f5f9;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-inverse: #ffffff;

  --border-subtle: #e2e8f0;
  --border-strong: #cbd5e1;
  --border-accent: #0284c7;

  --accent-primary: #0f172a;
  --accent-secondary: #0284c7;
  --accent-surface: #e0f2fe;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 12px 28px rgba(0, 0, 0, 0.1);

  --greek-color: #0369a1;
  --latin-color: #b91c1c;
}

/* ==========================================================================
   BASE RESET & GLOBAL STYLES
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  height: 100%;
}

body {
  min-height: 100vh;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  display: flex;
  flex-direction: column;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  cursor: pointer;
  font-family: inherit;
  background: none;
  border: none;
  color: inherit;
}

input, select, textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

/* ==========================================================================
   LAYOUT CONTAINERS
   ========================================================================== */
.app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.main-content {
  flex: 1;
  width: 100%;
  max-width: 1500px;
  margin: 0 auto;
  padding: var(--space-xl) var(--space-lg);
}

.main-content.fluid {
  max-width: 100%;
  padding: var(--space-md) var(--space-lg);
}

/* ==========================================================================
   HEADER & NAVBAR
   ========================================================================== */
.header-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-lg);
  box-shadow: var(--shadow-sm);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
  gap: var(--space-sm);
}

@media (max-width: 768px) {
  .header-nav {
    padding: 0 var(--space-sm);
  }

  .nav-links {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    max-width: 50vw;
  }

  .nav-links::-webkit-scrollbar {
    display: none;
  }

  .nav-link {
    padding: 0.35rem 0.5rem;
    font-size: 0.8rem;
    white-space: nowrap;
  }
}

.brand-section {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-title);
  font-weight: 700;
  font-size: 1.35rem;
  letter-spacing: 0.08em;
  color: var(--text-primary);
}

.brand-logo .brand-icon {
  font-size: 1.5rem;
}

.brand-tagline {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 400;
  display: none;
}

@media (min-width: 768px) {
  .brand-tagline {
    display: inline-block;
    border-left: 1px solid var(--border-strong);
    padding-left: var(--space-sm);
  }
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  list-style: none;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.85rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav-link:hover {
  color: var(--text-primary);
  background-color: var(--bg-secondary);
}

.nav-link.active {
  color: var(--accent-primary);
  background-color: var(--accent-surface);
  font-weight: 600;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.btn-search-trigger {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 0.4rem 0.9rem;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-pill);
  color: var(--text-secondary);
  font-size: 0.85rem;
  transition: all var(--transition-fast);
}

.btn-search-trigger:hover {
  background-color: var(--bg-surface-elevated);
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.kbd-shortcut {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.1rem 0.35rem;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
}

.btn-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.btn-icon:hover {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.app-footer {
  margin-top: auto;
  border-top: 1px solid var(--border-subtle);
  background-color: var(--bg-surface);
  padding: var(--space-xl) var(--space-lg);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.footer-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

@media (min-width: 768px) {
  .footer-content {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.footer-brand h4 {
  font-family: var(--font-title);
  color: var(--text-primary);
  margin-bottom: var(--space-xs);
}

.footer-links {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.footer-links a:hover {
  color: var(--accent-primary);
  text-decoration: underline;
}

/* Responsive Hide */
@media (max-width: 768px) {
  .hide-mobile {
    display: none !important;
  }
}