/**
 * BuildCalcWorld - Main CSS Design System
 * Professional dark theme with glassmorphism
 */

/* ============================================
   CSS Custom Properties (Design Tokens)
   ============================================ */
:root {
    /* Primary Colors - Construction Orange */
    --primary-50: #fff7ed;
    --primary-100: #ffedd5;
    --primary-200: #fed7aa;
    --primary-300: #fdba74;
    --primary-400: #fb923c;
    --primary-500: #f97316;
    --primary-600: #ea580c;
    --primary-700: #c2410c;
    --primary-800: #9a3412;
    --primary-900: #7c2d12;

    /* Secondary Colors - Steel Blue */
    --secondary-50: #f0f9ff;
    --secondary-100: #e0f2fe;
    --secondary-200: #bae6fd;
    --secondary-300: #7dd3fc;
    --secondary-400: #38bdf8;
    --secondary-500: #0ea5e9;
    --secondary-600: #0284c7;
    --secondary-700: #0369a1;
    --secondary-800: #075985;
    --secondary-900: #0c4a6e;

    /* Neutral Colors - Slate */
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    --gray-950: #020617;

    /* Semantic Colors */
    --success: #10b981;
    --success-light: #d1fae5;
    --warning: #f59e0b;
    --warning-light: #fef3c7;
    --error: #ef4444;
    --error-light: #fee2e2;
    --info: #3b82f6;
    --info-light: #dbeafe;

    /* Dark Theme Colors */
    --bg-primary: #0a0a0f;
    --bg-secondary: #111118;
    --bg-tertiary: #18181f;
    --bg-elevated: #1f1f28;
    --bg-card: rgba(255, 255, 255, 0.03);
    --bg-card-hover: rgba(255, 255, 255, 0.06);

    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-tertiary: #64748b;
    --text-muted: #475569;

    --border-primary: rgba(255, 255, 255, 0.08);
    --border-secondary: rgba(255, 255, 255, 0.05);
    --border-accent: rgba(249, 115, 22, 0.3);

    /* Glassmorphism */
    --glass-bg: rgba(255, 255, 255, 0.03);
    --glass-bg-strong: rgba(255, 255, 255, 0.06);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    --glass-blur: blur(12px);

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary-500), var(--primary-600));
    --gradient-secondary: linear-gradient(135deg, var(--secondary-500), var(--secondary-600));
    --gradient-dark: linear-gradient(180deg, var(--bg-primary), var(--bg-secondary));
    --gradient-glow: radial-gradient(ellipse at center, rgba(249, 115, 22, 0.15) 0%, transparent 70%);

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

    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;
    --text-5xl: 3rem;
    --text-6xl: 3.75rem;

    --leading-tight: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 40px rgba(249, 115, 22, 0.2);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
    --transition-slower: 500ms ease;

    /* Z-index */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal-backdrop: 400;
    --z-modal: 500;
    --z-tooltip: 600;

    /* Container */
    --container-max: 1280px;
    --container-padding: var(--space-6);
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    color: var(--text-primary);
    background: var(--bg-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

/* Background Pattern */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        var(--gradient-glow),
        radial-gradient(ellipse at 80% 20%, rgba(14, 165, 233, 0.08) 0%, transparent 50%),
        var(--bg-primary);
    pointer-events: none;
    z-index: -1;
}

/* Focus Styles */
:focus-visible {
    outline: 2px solid var(--primary-500);
    outline-offset: 2px;
}

/* Selection */
::selection {
    background: var(--primary-500);
    color: white;
}

/* Skip Link */
.skip-link {
    position: absolute;
    top: -100%;
    left: var(--space-4);
    padding: var(--space-3) var(--space-4);
    background: var(--primary-500);
    color: white;
    border-radius: var(--radius-md);
    z-index: var(--z-tooltip);
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: var(--space-4);
}

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

h1 {
    font-size: var(--text-5xl);
}

h2 {
    font-size: var(--text-4xl);
}

h3 {
    font-size: var(--text-3xl);
}

h4 {
    font-size: var(--text-2xl);
}

h5 {
    font-size: var(--text-xl);
}

h6 {
    font-size: var(--text-lg);
}

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

a {
    color: var(--primary-400);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-300);
}

strong {
    font-weight: 600;
}

small {
    font-size: var(--text-sm);
}

/* ============================================
   Container
   ============================================ */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* ============================================
   Header
   ============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-fixed);
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--border-primary);
    transition: all var(--transition-base);
}

.header.scrolled {
    background: rgba(10, 10, 15, 0.95);
}

.header-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
    gap: var(--space-6);
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    color: var(--text-primary);
    font-weight: 700;
    font-size: var(--text-lg);
    transition: opacity var(--transition-fast);
}

.logo:hover {
    opacity: 0.9;
    color: var(--text-primary);
}

.logo-icon {
    flex-shrink: 0;
}

.logo-accent {
    color: var(--primary-500);
}

/* Navigation */
.nav-main {
    display: none;
}

@media (min-width: 1024px) {
    .nav-main {
        display: block;
    }
}

.nav-list {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    list-style: none;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    color: var(--text-secondary);
    font-size: var(--text-sm);
    font-weight: 500;
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}

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

.nav-link.active {
    color: var(--primary-400);
    background: rgba(249, 115, 22, 0.1);
}

.nav-icon {
    flex-shrink: 0;
    opacity: 0.7;
}

/* Header Actions */
.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: transparent;
    border: none;
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: background var(--transition-fast);
}

.mobile-menu-toggle:hover {
    background: var(--glass-bg);
}

@media (min-width: 1024px) {
    .mobile-menu-toggle {
        display: none;
    }
}

.hamburger {
    display: flex;
    flex-direction: column;
    gap: 5px;
    width: 20px;
}

.hamburger span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Navigation */
.nav-mobile {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-primary);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-base);
    overflow-y: auto;
}

.nav-mobile.open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

@media (min-width: 1024px) {
    .nav-mobile {
        display: none;
    }
}

.nav-mobile-content {
    padding: var(--space-6);
}

.nav-mobile-list {
    list-style: none;
}

.nav-mobile-link {
    display: block;
    padding: var(--space-4);
    color: var(--text-primary);
    font-size: var(--text-lg);
    font-weight: 500;
    border-bottom: 1px solid var(--border-primary);
    transition: all var(--transition-fast);
}

.nav-mobile-link:hover {
    color: var(--primary-400);
    background: var(--glass-bg);
}

.nav-mobile-lang {
    margin-top: var(--space-8);
    padding-top: var(--space-6);
    border-top: 1px solid var(--border-primary);
}

/* ============================================
   Language Selector
   ============================================ */
.lang-selector {
    position: relative;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    background: var(--glass-bg);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-lg);
    color: var(--text-primary);
    font-size: var(--text-sm);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.lang-btn:hover {
    background: var(--glass-bg-strong);
    border-color: var(--border-accent);
}

.lang-flag {
    font-size: var(--text-lg);
}

.lang-arrow {
    transition: transform var(--transition-fast);
}

.lang-selector.open .lang-arrow {
    transform: rotate(180deg);
}

.lang-dropdown {
    position: absolute;
    top: calc(100% + var(--space-2));
    right: 0;
    min-width: 180px;
    background: var(--bg-elevated);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-fast);
    z-index: var(--z-dropdown);
}

.lang-selector.open .lang-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-option {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    color: var(--text-secondary);
    font-size: var(--text-sm);
    transition: all var(--transition-fast);
}

.lang-option:first-child {
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.lang-option:last-child {
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.lang-option:hover {
    background: var(--glass-bg);
    color: var(--text-primary);
}

.lang-option.active {
    color: var(--primary-400);
    background: rgba(249, 115, 22, 0.1);
}

.lang-check {
    margin-left: auto;
    color: var(--primary-500);
}

.lang-inline {
    display: flex;
    gap: var(--space-2);
}

.lang-inline-option {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--glass-bg);
    border-radius: var(--radius-md);
    font-size: var(--text-lg);
    transition: all var(--transition-fast);
}

.lang-inline-option:hover {
    background: var(--glass-bg-strong);
}

.lang-inline-option.active {
    background: rgba(249, 115, 22, 0.2);
    box-shadow: 0 0 0 2px var(--primary-500);
}

/* ============================================
   Main Content
   ============================================ */
.main {
    padding-top: 72px;
    min-height: 100vh;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-primary);
    padding: var(--space-16) 0 var(--space-8);
    margin-top: var(--space-24);
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-10);
}

@media (min-width: 640px) {
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .footer-grid {
        grid-template-columns: 2fr 1fr 1fr 1.5fr;
    }
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    color: var(--text-primary);
    font-weight: 700;
    font-size: var(--text-lg);
    margin-bottom: var(--space-4);
}

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

.footer-description {
    font-size: var(--text-sm);
    margin-bottom: var(--space-6);
    max-width: 300px;
}

.social-links {
    display: flex;
    gap: var(--space-3);
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--glass-bg);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.social-link:hover {
    background: var(--primary-500);
    color: white;
    transform: translateY(-2px);
}

.footer-title {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-4);
}

.footer-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.footer-list a {
    color: var(--text-secondary);
    font-size: var(--text-sm);
    transition: color var(--transition-fast);
}

.footer-list a:hover {
    color: var(--primary-400);
}

/* Newsletter */
.newsletter-form {
    margin-bottom: var(--space-6);
}

.newsletter-input-group {
    display: flex;
    gap: var(--space-2);
}

.newsletter-input {
    flex: 1;
    padding: var(--space-3) var(--space-4);
    background: var(--glass-bg);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-lg);
    color: var(--text-primary);
    font-size: var(--text-sm);
    transition: all var(--transition-fast);
}

.newsletter-input:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px rgba(249, 115, 22, 0.1);
}

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

.newsletter-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: var(--gradient-primary);
    border: none;
    border-radius: var(--radius-lg);
    color: white;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.newsletter-btn:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-glow);
}

.newsletter-btn:active {
    transform: scale(1);
}

.footer-lang {
    padding-top: var(--space-4);
}

/* Footer Bottom */
.footer-bottom {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    padding-top: var(--space-8);
    margin-top: var(--space-10);
    border-top: 1px solid var(--border-primary);
}

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

.copyright {
    font-size: var(--text-sm);
    color: var(--text-muted);
}

.footer-legal {
    display: flex;
    gap: var(--space-6);
}

.footer-legal a {
    color: var(--text-muted);
    font-size: var(--text-sm);
    transition: color var(--transition-fast);
}

.footer-legal a:hover {
    color: var(--text-secondary);
}

/* ============================================
   Utility Classes
   ============================================ */
.text-primary {
    color: var(--text-primary);
}

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

.text-accent {
    color: var(--primary-500);
}

.bg-glass {
    background: var(--glass-bg);
}

.bg-elevated {
    background: var(--bg-elevated);
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}