/**
 * KT-Telecom Corporate Styles
 * Modern hyperscaler / digital infrastructure style
 * Inspired by: Google Cloud, AWS, Equinix, Digital Realty
 */

/* ===== CSS VARIABLES ===== */
:root {
    /* Colors - спокойная корпоративная палитра */
    --color-primary: #2563eb;
    --color-primary-dark: #1e40af;
    --color-primary-light: #60a5fa;
    --color-secondary: #475569;
    --color-accent: #0ea5e9;
    
    --color-text: #1e293b;
    --color-text-light: #64748b;
    --color-text-lighter: #94a3b8;
    
    --color-bg: #ffffff;
    --color-bg-light: #f8fafc;
    --color-bg-gray: #f1f5f9;
    --color-border: #e2e8f0;
    
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-danger: #ef4444;
    
    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', monospace;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Border radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition: all 0.2s ease;
}

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

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

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

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

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

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

/* ===== LAYOUT ===== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.container-wide {
    max-width: 1400px;
}

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

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

/* ===== HEADER ===== */
.header {
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.95);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) var(--spacing-lg);
    min-height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
}

.logo img {
    height: 40px;
    width: auto;
}

.nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-2xl);
}

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

.nav-link {
    color: var(--color-text);
    font-size: 0.95rem;
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

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

.nav-link.active {
    color: var(--color-primary);
}

/* Language Switcher */
.lang-switcher {
    display: flex;
    gap: var(--spacing-xs);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-xs);
    background-color: var(--color-bg-light);
}

.lang-switcher a {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-light);
    border-radius: var(--radius-sm);
    text-transform: uppercase;
    transition: var(--transition);
}

.lang-switcher a:hover {
    background-color: var(--color-bg);
    color: var(--color-primary);
}

.lang-switcher a.active {
    background-color: var(--color-primary);
    color: white;
}

/* Mobile menu toggle */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.mobile-menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-text);
    margin: 5px 0;
    transition: var(--transition);
}

/* ===== HERO SECTION ===== */
.hero {
    background: linear-gradient(135deg, #f8fafc 0%, #e0e7ff 100%);
    padding: var(--spacing-3xl) 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-2xl);
    line-height: 1.6;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* ===== BUTTONS ===== */
.btn {
    display: inline-block;
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

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

.btn-primary:hover {
    background-color: var(--color-primary-dark);
    color: white;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
    background-color: var(--color-primary);
    color: white;
}

.btn-ghost {
    background-color: transparent;
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-ghost:hover {
    background-color: var(--color-bg-light);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    color: var(--color-text);
}

h1 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
}

h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
}

h4 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-light);
}

/* ===== CARDS ===== */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.card {
    background-color: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    transition: var(--transition);
}

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

.card-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background-color: var(--color-bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-lg);
    font-size: 1.5rem;
    color: var(--color-primary);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.card-text {
    color: var(--color-text-light);
    line-height: 1.6;
}

/* ===== PROCUREMENT CARDS ===== */
.procurement-card {
    background-color: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    transition: var(--transition);
}

.procurement-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary-light);
}

.procurement-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: var(--spacing-md);
    gap: var(--spacing-md);
}

.procurement-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
}

.procurement-amount {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    white-space: nowrap;
}

.procurement-meta {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    color: var(--color-text-light);
    font-size: 0.875rem;
    margin-top: var(--spacing-md);
}

.procurement-meta-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.procurement-status {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
}

.status-active {
    background-color: #d1fae5;
    color: #065f46;
}

.status-closed {
    background-color: #e5e7eb;
    color: #374151;
}

.status-cancelled {
    background-color: #fee2e2;
    color: #991b1b;
}

/* ===== FILES LIST ===== */
.files-list {
    list-style: none;
    margin-top: var(--spacing-md);
}

.file-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--color-bg-light);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-sm);
    transition: var(--transition);
}

.file-item:hover {
    background-color: var(--color-bg-gray);
}

.file-item a {
    color: var(--color-text);
    flex: 1;
}

/* ===== FORMS ===== */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
    color: var(--color-text);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: var(--font-sans);
    transition: var(--transition);
    background-color: var(--color-bg);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-textarea {
    min-height: 120px;
    resize: vertical;
}

.form-hint {
    font-size: 0.875rem;
    color: var(--color-text-lighter);
    margin-top: var(--spacing-xs);
}

.form-error {
    color: var(--color-danger);
    font-size: 0.875rem;
    margin-top: var(--spacing-xs);
}

/* ===== ALERTS ===== */
.alert {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

.alert-success {
    background-color: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.alert-error {
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.alert-info {
    background-color: #dbeafe;
    color: #1e40af;
    border: 1px solid #bfdbfe;
}

/* ===== FOOTER ===== */
.footer {
    background-color: var(--color-bg-gray);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-2xl) 0;
    margin-top: var(--spacing-3xl);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
}

.footer-text {
    color: var(--color-text-light);
    font-size: 0.875rem;
}

.footer-links {
    display: flex;
    gap: var(--spacing-lg);
    list-style: none;
}

.footer-link {
    color: var(--color-text-light);
    font-size: 0.875rem;
    transition: var(--transition);
}

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

/* ===== ADMIN STYLES ===== */
.admin-header {
    background-color: var(--color-text);
    color: white;
    padding: var(--spacing-md) 0;
    margin-bottom: var(--spacing-xl);
}

.admin-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.admin-nav a {
    color: white;
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
    background-color: var(--color-bg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.admin-table th {
    background-color: var(--color-bg-gray);
    padding: var(--spacing-md);
    text-align: left;
    font-weight: 600;
    color: var(--color-text);
    border-bottom: 2px solid var(--color-border);
}

.admin-table td {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
}

.admin-table tr:hover {
    background-color: var(--color-bg-light);
}

.admin-actions {
    display: flex;
    gap: var(--spacing-sm);
}

.btn-sm {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.875rem;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background-color: white;
        flex-direction: column;
        padding: var(--spacing-lg);
        border-bottom: 1px solid var(--color-border);
        box-shadow: var(--shadow-md);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .card-grid {
        grid-template-columns: 1fr;
    }
    
    .procurement-header {
        flex-direction: column;
        align-items: start;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}

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

.text-muted {
    color: var(--color-text-light);
}

.mt-1 { margin-top: var(--spacing-md); }
.mt-2 { margin-top: var(--spacing-lg); }
.mt-3 { margin-top: var(--spacing-xl); }

.mb-1 { margin-bottom: var(--spacing-md); }
.mb-2 { margin-bottom: var(--spacing-lg); }
.mb-3 { margin-bottom: var(--spacing-xl); }

.hidden {
    display: none;
}