/**
 * DigitalStackHub Main Stylesheet
 * 
 * @package DigitalStackHub
 * @version 1.0.0
 */

/* ============================================
   CSS VARIABLES - LIGHT MODE (DEFAULT)
   ============================================ */
:root {
    /* Colors */
    --color-primary: #6366F1;
    --color-primary-dark: #4F46E5;
    --color-primary-light: #818CF8;
    --color-secondary: #8B5CF6;
    --color-accent: #EC4899;
    --color-success: #10B981;
    --color-warning: #F59E0B;
    --color-danger: #EF4444;
    --color-info: #3B82F6;
    
    /* Backgrounds */
    --bg-primary: #F8FAFC;
    --bg-secondary: #F1F5F9;
    --bg-tertiary: #E2E8F0;
    
    /* Glassmorphism */
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.2);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    --glass-blur: blur(12px);
    
    /* Text */
    --text-primary: #0F172A;
    --text-secondary: #475569;
    --text-tertiary: #64748B;
    --text-inverse: #FFFFFF;
    
    /* Borders */
    --border-color: #E2E8F0;
    --border-light: #F1F5F9;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-2xl: 32px;
    --radius-full: 9999px;
    
    /* Typography */
    --font-family-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --font-family-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Layout */
    --container-width: 1280px;
    --header-height: 80px;
    --header-height-mobile: 70px;
}

/* ============================================
   DARK MODE VARIABLES
   ============================================ */
[data-theme="dark"] {
    /* Backgrounds */
    --bg-primary: #0F172A;
    --bg-secondary: #1E293B;
    --bg-tertiary: #334155;
    
    /* Glassmorphism */
    --glass-bg: rgba(15, 23, 42, 0.7);
    --glass-border: rgba(255, 255, 255, 0.05);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    
    /* Text */
    --text-primary: #F8FAFC;
    --text-secondary: #CBD5E1;
    --text-tertiary: #94A3B8;
    
    /* Borders */
    --border-color: #334155;
    --border-light: #1E293B;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.25);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.35);
}

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

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

body {
    font-family: var(--font-family-body);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    transition: background-color var(--transition-normal), color var(--transition-normal);
    overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-family-heading);
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

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

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

/* ============================================
   GLASSMORPHISM COMPONENTS
   ============================================ */
.glass-card,
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--glass-shadow);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.glass-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.glass-nav {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--glass-border);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.glass-footer {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border-top: 1px solid var(--glass-border);
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    line-height: 1;
    text-align: center;
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
    cursor: pointer;
    border: none;
    background: transparent;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: white;
}

.btn-secondary {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: rgba(99, 102, 241, 0.1);
    border-color: var(--color-primary);
    transform: translateY(-2px);
}

.btn-outline {
    border: 2px solid var(--color-primary);
    color: var(--color-primary);
    background: transparent;
}

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

.btn-danger {
    background: var(--color-danger);
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
    transform: translateY(-2px);
}

.btn-success {
    background: var(--color-success);
    color: white;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-block {
    width: 100%;
    display: flex;
}

/* ============================================
   CONTAINER & LAYOUT
   ============================================ */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    width: 100%;
}

.section {
    padding: var(--spacing-2xl) 0;
}

.section-sm {
    padding: var(--spacing-xl) 0;
}

.section-lg {
    padding: var(--spacing-3xl) 0;
}

/* Grid System */
.grid {
    display: grid;
    gap: var(--spacing-lg);
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

.grid-5 {
    grid-template-columns: repeat(5, 1fr);
}

/* ============================================
   HEADER & NAVIGATION
   ============================================ */
.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--header-height);
}

.site-branding {
    flex-shrink: 0;
}

.site-logo img {
    max-height: 50px;
    width: auto;
}

.site-title a {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.main-navigation ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    margin: 0;
    padding: 0;
}

.main-navigation li a {
    color: var(--text-primary);
    font-weight: 500;
    padding: var(--spacing-xs) 0;
}

.main-navigation li a:hover {
    color: var(--color-primary);
}

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

.theme-toggle {
    margin-left: var(--spacing-sm);
}

.theme-toggle input {
    display: none;
}

.toggle-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-full);
    background: var(--glass-bg);
}

.sun-icon, .moon-icon {
    font-size: 1.25rem;
    transition: opacity var(--transition-fast);
}

[data-theme="light"] .moon-icon,
[data-theme="dark"] .sun-icon {
    display: none;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.mobile-menu-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-fast);
}

.mobile-navigation {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--glass-border);
    padding: var(--spacing-md);
}

.mobile-navigation.active {
    display: block;
}

/* ============================================
   FORMS
   ============================================ */
input,
textarea,
select {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    font-family: var(--font-family-body);
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
}

input:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
    color: var(--text-primary);
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.animate-fade-in-up {
    animation: fadeInUp 0.6s ease forwards;
}

.animate-fade-in {
    animation: fadeIn 0.5s ease forwards;
}

.animate-slide-left {
    animation: slideInLeft 0.5s ease forwards;
}

.animate-slide-right {
    animation: slideInRight 0.5s ease forwards;
}

/* Scroll Reveal Classes */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.p-0 { padding: 0; }
.p-1 { padding: var(--spacing-xs); }
.p-2 { padding: var(--spacing-sm); }
.p-3 { padding: var(--spacing-md); }
.p-4 { padding: var(--spacing-lg); }
.p-5 { padding: var(--spacing-xl); }

.rounded-sm { border-radius: var(--radius-sm); }
.rounded-md { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: var(--radius-full); }

.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

/* ============================================
   FOOTER
   ============================================ */
.site-footer {
    margin-top: var(--spacing-2xl);
}

.footer-widgets {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    padding: var(--spacing-2xl) 0;
}

.footer-widget-title {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    padding: var(--spacing-lg) 0;
    border-top: 1px solid var(--border-color);
}

.footer-menu ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    margin: 0;
    padding: 0;
}

.footer-menu li a {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

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

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 1024px) {
    :root {
        --container-width: 100%;
    }
    
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    h3 { font-size: 1.5rem; }
    
    .grid-4,
    .grid-5 {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    .main-navigation {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .grid-2,
    .grid-3,
    .grid-4,
    .grid-5 {
        grid-template-columns: 1fr;
    }
    
    .section {
        padding: var(--spacing-xl) 0;
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
    
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.25rem; }
    
    .btn {
        padding: 0.625rem 1.25rem;
    }
    
    .footer-widgets {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-menu ul {
        flex-wrap: wrap;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    h1 { font-size: 1.75rem; }
    h2 { font-size: 1.5rem; }
    
    .section {
        padding: var(--spacing-lg) 0;
    }
    
    .header-actions .btn {
        display: none;
    }
}