/**
 * Chess Hub Design System
 * A unified design system for the Chess Hub application
 * Used by all apps except the accounts app
 */

/* ============================================================================
   CSS VARIABLES / DESIGN TOKENS
   ============================================================================ */

:root {
    /* Colors - Primary Theme */
    --color-primary: #667eea;
    --color-primary-dark: #764ba2;
    --color-primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);

    /* Colors - Semantics */
    --color-success: #155724;
    --color-success-bg: #d4edda;
    --color-success-border: #c3e6cb;

    --color-error: #721c24;
    --color-error-bg: #f8d7da;
    --color-error-border: #f5c6cb;

    --color-warning: #856404;
    --color-warning-bg: #fff3cd;
    --color-warning-border: #ffeeba;

    --color-danger: #dc3545;
    --color-danger-hover: #c82333;

    /* Colors - Grayscale */
    --color-text: #333;
    --color-text-light: #666;
    --color-text-lighter: #999;
    --color-bg: #f5f5f5;
    --color-bg-light: #f0f0f0;
    --color-border: #ddd;
    --color-border-light: #e0e0e0;
    --color-card: #ffffff;

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 14px;
    --font-size-xs: 12px;
    --font-size-lg: 18px;
    --font-size-xl: 22px;
    --font-size-2xl: 28px;

    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    --line-height-base: 1.5;
    --line-height-heading: 1.3;

    /* Spacing Scale */
    --spacing-xs: 5px;
    --spacing-sm: 10px;
    --spacing-md: 20px;
    --spacing-lg: 30px;
    --spacing-xl: 40px;

    /* Border Radius */
    --border-radius-sm: 6px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;

    /* Shadows */
    --shadow-xs: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 20px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 10px 30px rgba(0, 0, 0, 0.2);
    --shadow-primary: 0 5px 15px rgba(102, 126, 234, 0.4);

    /* Transitions */
    --transition-fast: 0.2s;
    --transition-normal: 0.3s;

    /* Breakpoints (mobile-first) */
    --breakpoint-sm: 480px;
    --breakpoint-md: 768px;
    --breakpoint-lg: 1024px;
    --breakpoint-xl: 1280px;

    /* Navigation dimensions */
    --nav-sidebar-width: 250px;
    --nav-sidebar-collapsed-width: 64px;
    --nav-bottom-bar-height: 64px;
}

/* ============================================================================
   RESET & NORMALIZE
   ============================================================================ */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-family);
    background: var(--color-bg);
    min-height: 100vh;
    color: var(--color-text);
    line-height: var(--line-height-base);
}

/* ============================================================================
   TYPOGRAPHY
   ============================================================================ */

h1 {
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-semibold);
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
    line-height: var(--line-height-heading);
}

h2 {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-semibold);
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
    line-height: var(--line-height-heading);
}

h3 {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
    line-height: var(--line-height-heading);
}

h4, h5, h6 {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-semibold);
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

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

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

a:hover {
    text-decoration: underline;
}

.subtitle {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-lg);
    font-size: var(--font-size-sm);
}

/* ============================================================================
   CONTAINER & LAYOUT
   ============================================================================ */

.container {
    width: 100%;
    padding: var(--spacing-lg) var(--spacing-xl);
    display: flex;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    min-height: 100%;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.main-content {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    flex: 1;
    background: var(--color-bg);
}

.main-content > .container {
    flex: 1;
}

/* ============================================================================
   MESSAGES & ALERTS
   ============================================================================ */

.messages {
    margin-bottom: var(--spacing-md);
    width: 100%;
}

.alert {
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius-sm);
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-sm);
    border: 1px solid;
}

.alert-success {
    background-color: var(--color-success-bg);
    color: var(--color-success);
    border-color: var(--color-success-border);
}

.alert-error {
    background-color: var(--color-error-bg);
    color: var(--color-error);
    border-color: var(--color-error-border);
}

.alert-warning {
    background-color: var(--color-warning-bg);
    color: var(--color-warning);
    border-color: var(--color-warning-border);
}

.alert-info {
    background-color: #cfe2ff;
    color: #084298;
    border-color: #b6d4fe;
}

/* ============================================================================
   TOAST NOTIFICATIONS
   ============================================================================ */

.toast-container {
    position: fixed;
    bottom: calc(var(--bottom-nav-height, 64px) + var(--spacing-md));
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column-reverse;
    align-items: center;
    gap: var(--spacing-sm);
    z-index: 9999;
    pointer-events: none;
    width: min(calc(100vw - 2 * var(--spacing-md)), 480px);
}

.toast {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius-sm);
    border: 1px solid;
    font-size: var(--font-size-sm);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    pointer-events: auto;
    width: 100%;
    opacity: 1;
    transition: opacity 0.4s ease, transform 0.4s ease;
    animation: toast-in 0.3s ease;
}

.toast.toast-hiding {
    opacity: 0;
    transform: translateY(8px);
}

@keyframes toast-in {
    from { opacity: 0; transform: translateY(12px); }
    to   { opacity: 1; transform: translateY(0); }
}

.toast-message {
    flex: 1;
}

.toast-close {
    flex-shrink: 0;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    line-height: 1;
    padding: 0 0 0 var(--spacing-sm);
    opacity: 0.6;
    color: inherit;
}

.toast-close:hover {
    opacity: 1;
}

.toast-success {
    background-color: var(--color-success-bg);
    color: var(--color-success);
    border-color: var(--color-success-border);
}

.toast-error {
    background-color: var(--color-error-bg);
    color: var(--color-error);
    border-color: var(--color-error-border);
}

.toast-warning {
    background-color: var(--color-warning-bg);
    color: var(--color-warning);
    border-color: var(--color-warning-border);
}

.toast-info {
    background-color: #cfe2ff;
    color: #084298;
    border-color: #b6d4fe;
}

/* On desktop, show toasts in the bottom-right corner instead */
@media (min-width: 768px) {
    .toast-container {
        left: auto;
        right: var(--spacing-lg, 24px);
        transform: none;
        align-items: flex-end;
        bottom: var(--spacing-lg, 24px);
    }
}

/* ============================================================================
   RESPONSIVE UTILITIES
   ============================================================================ */

/* Mobile-first responsive utilities */
@media (max-width: 480px) {
    h1 {
        font-size: 24px;
    }

    h2 {
        font-size: 18px;
    }

    .container {
        padding: var(--spacing-sm);
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .container {
        padding: var(--spacing-md) var(--spacing-lg);
    }
}

@media (max-width: 768px) {
    .container {
        padding: var(--spacing-md);
    }
}