/**
 * Badminton Tournament Portal - Main CSS
 * Moderní modrý design s plnou responzivitou
 */

/* ========================================
   CSS Variables (Custom Properties)
   ======================================== */
:root {
    /* Modrá barevná paleta */
    --color-primary: #1e40af;
    --color-primary-dark: #1e3a8a;
    --color-primary-light: #3b82f6;
    --color-primary-lighter: #60a5fa;
    --color-accent: #0ea5e9;

    /* Neutralní barvy */
    --color-white: #ffffff;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;

    /* Stavové barvy */
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-error: #ef4444;
    --color-info: #3b82f6;

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;

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

    /* Border radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.375rem;
    --radius-lg: 0.5rem;
    --radius-xl: 0.75rem;
    --radius-2xl: 1rem;
    --radius-full: 9999px;

    /* 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), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Container */
    --container-max-width: 1280px;
}

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

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

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-gray-800);
    background-color: var(--color-gray-50);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ========================================
   Typography
   ======================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-4);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

p {
    margin-bottom: var(--spacing-4);
}

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

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

/* ========================================
   Layout
   ======================================== */
.container {
    width: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-4);
}

@media (min-width: 640px) {
    .container { padding: 0 var(--spacing-6); }
}

@media (min-width: 1024px) {
    .container { padding: 0 var(--spacing-8); }
}

/* ========================================
   Header & Navigation
   ======================================== */
.header {
    background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 100%);
    color: var(--color-white);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-4) 0;
}

.logo {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-white);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.logo:hover {
    color: var(--color-white);
    text-decoration: none;
    opacity: 0.9;
}

.nav {
    display: flex;
    gap: var(--spacing-6);
    align-items: center;
}

.nav a {
    color: var(--color-white);
    font-weight: 500;
    padding: var(--spacing-2) var(--spacing-3);
    border-radius: var(--radius-md);
    transition: background-color var(--transition-fast);
}

.nav a:hover {
    background-color: rgba(255, 255, 255, 0.1);
    text-decoration: none;
}

.nav a.active {
    background-color: rgba(255, 255, 255, 0.2);
}

.mobile-menu-button {
    display: none;
    background: none;
    border: none;
    color: var(--color-white);
    font-size: var(--font-size-2xl);
    cursor: pointer;
    padding: var(--spacing-2);
}

@media (max-width: 768px) {
    .mobile-menu-button {
        display: block;
    }

    .nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--color-primary-dark);
        flex-direction: column;
        padding: var(--spacing-4);
        box-shadow: var(--shadow-lg);
    }

    .nav.active {
        display: flex;
    }
}

/* ========================================
   Main Content
   ======================================== */
.main-content {
    flex: 1;
    padding: var(--spacing-8) 0;
}

/* ========================================
   Cards
   ======================================== */
.card {
    background: var(--color-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-6);
    margin-bottom: var(--spacing-6);
}

.card-header {
    border-bottom: 2px solid var(--color-gray-100);
    padding-bottom: var(--spacing-4);
    margin-bottom: var(--spacing-6);
}

.card-title {
    margin: 0;
    color: var(--color-primary);
}

.card-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-6);
}

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

@media (min-width: 1024px) {
    .card-grid { grid-template-columns: repeat(3, 1fr); }
}

/* ========================================
   Buttons
   ======================================== */
.btn {
    display: inline-block;
    padding: var(--spacing-3) var(--spacing-6);
    font-size: var(--font-size-base);
    font-weight: 600;
    text-align: center;
    text-decoration: none;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    line-height: 1.5;
}

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

.btn-primary:hover {
    background: var(--color-primary-dark);
    text-decoration: none;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--color-gray-200);
    color: var(--color-gray-800);
}

.btn-secondary:hover {
    background: var(--color-gray-300);
    text-decoration: none;
}

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

.btn-success:hover {
    background: #059669;
    text-decoration: none;
}

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

.btn-danger:hover {
    background: #dc2626;
    text-decoration: none;
}

.btn-sm {
    padding: var(--spacing-2) var(--spacing-4);
    font-size: var(--font-size-sm);
}

.btn-lg {
    padding: var(--spacing-4) var(--spacing-8);
    font-size: var(--font-size-lg);
}

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

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ========================================
   Forms
   ======================================== */
.form-group {
    margin-bottom: var(--spacing-5);
}

.form-label {
    display: block;
    font-weight: 600;
    margin-bottom: var(--spacing-2);
    color: var(--color-gray-700);
}

.form-label.required::after {
    content: ' *';
    color: var(--color-error);
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: var(--spacing-3) var(--spacing-4);
    font-size: var(--font-size-base);
    line-height: 1.5;
    color: var(--color-gray-800);
    background: var(--color-white);
    border: 2px solid var(--color-gray-300);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(30, 64, 175, 0.1);
}

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

.form-error {
    color: var(--color-error);
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-2);
}

.form-help {
    color: var(--color-gray-500);
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-2);
}

/* ========================================
   Alerts & Messages
   ======================================== */
.alert {
    padding: var(--spacing-4) var(--spacing-5);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-6);
    border-left: 4px solid;
}

.alert-success {
    background: #d1fae5;
    border-color: var(--color-success);
    color: #065f46;
}

.alert-error {
    background: #fee2e2;
    border-color: var(--color-error);
    color: #991b1b;
}

.alert-warning {
    background: #fef3c7;
    border-color: var(--color-warning);
    color: #92400e;
}

.alert-info {
    background: #dbeafe;
    border-color: var(--color-info);
    color: #1e40af;
}

/* ========================================
   Tables
   ======================================== */
.table {
    width: 100%;
    border-collapse: collapse;
    background: var(--color-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.table thead {
    background: var(--color-gray-100);
}

.table th {
    padding: var(--spacing-4);
    text-align: left;
    font-weight: 600;
    color: var(--color-gray-700);
    border-bottom: 2px solid var(--color-gray-200);
}

.table td {
    padding: var(--spacing-4);
    border-bottom: 1px solid var(--color-gray-200);
}

.table tbody tr:hover {
    background: var(--color-gray-50);
}

.table-responsive {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background: var(--color-gray-900);
    color: var(--color-gray-300);
    padding: var(--spacing-8) 0;
    margin-top: auto;
}

.footer a {
    color: var(--color-gray-300);
}

.footer a:hover {
    color: var(--color-white);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-8);
}

@media (min-width: 768px) {
    .footer-content {
        grid-template-columns: repeat(3, 1fr);
    }
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-8);
    margin-top: var(--spacing-8);
    border-top: 1px solid var(--color-gray-700);
    color: var(--color-gray-500);
}

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

.mt-0 { margin-top: 0; }
.mt-2 { margin-top: var(--spacing-2); }
.mt-4 { margin-top: var(--spacing-4); }
.mt-6 { margin-top: var(--spacing-6); }
.mt-8 { margin-top: var(--spacing-8); }

.mb-0 { margin-bottom: 0; }
.mb-2 { margin-bottom: var(--spacing-2); }
.mb-4 { margin-bottom: var(--spacing-4); }
.mb-6 { margin-bottom: var(--spacing-6); }
.mb-8 { margin-bottom: var(--spacing-8); }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-2 { gap: var(--spacing-2); }
.gap-4 { gap: var(--spacing-4); }
.gap-6 { gap: var(--spacing-6); }

.hidden { display: none; }

@media (max-width: 640px) {
    .sm\:hidden { display: none; }
}

@media (max-width: 768px) {
    .md\:hidden { display: none; }
}

/* ========================================
   Loading Spinner
   ======================================== */
.spinner {
    border: 3px solid var(--color-gray-200);
    border-top-color: var(--color-primary);
    border-radius: var(--radius-full);
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ========================================
   Modal
   ======================================== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    padding: var(--spacing-4);
}

.modal {
    background: var(--color-white);
    border-radius: var(--radius-xl);
    max-width: 600px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
}

.modal-header {
    padding: var(--spacing-6);
    border-bottom: 1px solid var(--color-gray-200);
}

.modal-body {
    padding: var(--spacing-6);
}

.modal-footer {
    padding: var(--spacing-6);
    border-top: 1px solid var(--color-gray-200);
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-3);
}