/**
 * CORE.CSS - Estilos Base y Sistema de Diseño
 * Modular, Responsive, Optimizado
 * Soporta: macOS Desktop, iOS/iPadOS Mobile
 */

/* ============================================
   VARIABLES CSS - Design System
   ============================================ */
:root {
    /* Colores */
    --color-primary: #007AFF;
    --color-primary-dark: #0051D5;
    --color-primary-light: #5AC8FA;
    --color-secondary: #5AC8FA;
    --color-success: #34C759;
    --color-warning: #FF9500;
    --color-danger: #FF3B30;
    --color-error: #FF3B30;
    
    /* Escala de grises */
    --color-background: #FFFFFF;
    --color-background-secondary: #F2F2F7;
    --color-text: #000000;
    --color-text-secondary: #666666;
    --color-text-tertiary: #999999;
    --color-border: #E5E5EA;
    --color-border-light: #F0F0F0;
    
    /* Dark mode */
    --color-bg-dark: #000000;
    --color-bg-dark-secondary: #1C1C1E;
    --color-text-dark: #FFFFFF;
    --color-border-dark: #424245;
    
    /* Espaciado */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;
    --spacing-xl: 24px;
    --spacing-2xl: 32px;
    --spacing-3xl: 48px;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'SF Pro Display', Helvetica, Arial, sans-serif;
    --font-size-xs: 12px;
    --font-size-sm: 13px;
    --font-size-base: 16px;
    --font-size-lg: 18px;
    --font-size-xl: 20px;
    --font-size-2xl: 24px;
    --font-size-3xl: 32px;
    
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    --line-height-tight: 1.2;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;
    
    /* Bordes */
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;
    --border-radius-xl: 16px;
    --border-radius-full: 9999px;
    
    /* Sombras */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1);
    
    /* Transiciones */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
    
    /* Z-index */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-modal: 1000;
    --z-tooltip: 1100;
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
    :root {
        --color-background: var(--color-bg-dark);
        --color-background-secondary: var(--color-bg-dark-secondary);
        --color-text: var(--color-text-dark);
        --color-border: var(--color-border-dark);
    }
}

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

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

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--color-text);
    background-color: transparent;
    overflow-x: hidden;
}

/* Tipografía */
h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-weight-semibold);
    line-height: var(--line-height-tight);
    margin-bottom: var(--spacing-md);
}

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

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

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

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

/* Inputs */
input, textarea, select {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
}

button {
    font-family: var(--font-family);
    cursor: pointer;
    border: none;
    background: none;
}

/* ============================================
   COMPONENTES BASE
   ============================================ */

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

.container-sm {
    max-width: 640px;
}

.container-md {
    max-width: 896px;
}

.container-lg {
    max-width: 1280px;
}

/* Flexbox utilities */
.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.flex-wrap {
    flex-wrap: wrap;
}

.gap-xs { gap: var(--spacing-xs); }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }
.gap-xl { gap: var(--spacing-xl); }

/* Grid */
.grid {
    display: grid;
    grid-auto-flow: row;
}

.grid-cols-1 { grid-template-columns: 1fr; }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

/* Espaciado */
.m-0 { margin: 0; }
.m-xs { margin: var(--spacing-xs); }
.m-sm { margin: var(--spacing-sm); }
.m-md { margin: var(--spacing-md); }
.m-lg { margin: var(--spacing-lg); }
.m-xl { margin: var(--spacing-xl); }

.mx-auto { margin-left: auto; margin-right: auto; }

.p-0 { padding: 0; }
.p-xs { padding: var(--spacing-xs); }
.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

/* Visibilidad */
.hidden {
    display: none !important;
}

.invisible {
    visibility: hidden;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* ============================================
   BOTONES
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-semibold);
    transition: all var(--transition-base);
    user-select: none;
    
    /* Accesibilidad */
    &:focus-visible {
        outline: 2px solid var(--color-primary);
        outline-offset: 2px;
    }
    
    &:disabled {
        opacity: 0.5;
        cursor: not-allowed;
    }
}

/* Primario */
.btn-primary {
    background-color: var(--color-primary);
    color: white;
    
    &:hover:not(:disabled) {
        background-color: var(--color-primary-dark);
    }
    
    &:active:not(:disabled) {
        transform: scale(0.98);
    }
}

/* Secundario */
.btn-secondary {
    background-color: var(--color-background-secondary);
    color: var(--color-text);
    
    &:hover:not(:disabled) {
        background-color: var(--color-border);
    }
}

/* Outline */
.btn-outline {
    border: 1px solid var(--color-primary);
    color: var(--color-primary);
    background-color: transparent;
    
    &:hover:not(:disabled) {
        background-color: var(--color-primary);
        color: white;
    }
}

/* Tamaños */
.btn-sm {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-sm);
}

.btn-lg {
    padding: var(--spacing-lg) var(--spacing-xl);
    font-size: var(--font-size-lg);
    min-height: 56px; /* iOS safe */
}

.btn-full {
    width: 100%;
}

/* Link button */
.link-button {
    background: none;
    border: none;
    padding: 0;
    color: var(--color-primary);
    font-size: var(--font-size-base);
    text-decoration: underline;
    cursor: pointer;
    transition: opacity var(--transition-fast);
    
    &:hover:not(:disabled) {
        opacity: 0.7;
    }
    
    &:disabled {
        opacity: 0.5;
        cursor: not-allowed;
    }
}

/* Spinner */
.btn-spinner {
    width: 16px;
    height: 16px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

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

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

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
    font-size: var(--font-size-base);
    transition: all var(--transition-base);
    background-color: var(--color-background);
    color: var(--color-text);
    
    &::placeholder {
        color: var(--color-text-tertiary);
    }
    
    &:focus {
        outline: none;
        border-color: var(--color-primary);
        box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.1);
    }
    
    &:invalid:not(:placeholder-shown) {
        border-color: var(--color-danger);
        box-shadow: 0 0 0 3px rgba(255, 59, 48, 0.1);
    }
}

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

.form-hint {
    display: block;
    margin-top: var(--spacing-sm);
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
}

/* ============================================
   MENSAJES
   ============================================ */
.error-message,
.success-message,
.warning-message,
.info-message {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-md);
}

.error-message {
    background-color: rgba(255, 59, 48, 0.1);
    color: var(--color-danger);
    border-left: 3px solid var(--color-danger);
}

.success-message {
    background-color: rgba(52, 199, 89, 0.1);
    color: var(--color-success);
    border-left: 3px solid var(--color-success);
}

.warning-message {
    background-color: rgba(255, 149, 0, 0.1);
    color: var(--color-warning);
    border-left: 3px solid var(--color-warning);
}

.info-message {
    background-color: rgba(0, 122, 255, 0.1);
    color: var(--color-primary);
    border-left: 3px solid var(--color-primary);
}

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

/* iPhone 13 mini (375px) */
@media (max-width: 480px) {
    :root {
        --spacing-lg: 12px;
        --spacing-xl: 16px;
        --font-size-base: 14px;
    }

    /* Inputs nunca bajan de 16px — iOS Safari hace zoom si font-size < 16px */
    input, textarea, select {
        font-size: 16px !important;
    }
    
    h1 { font-size: var(--font-size-2xl); }
    h2 { font-size: var(--font-size-xl); }
    
    .btn-lg {
        min-height: 48px;
    }
}

/* Tablets */
@media (min-width: 768px) {
    .container {
        padding: 0 var(--spacing-xl);
    }
    
    .grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
    .grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
}

/* Desktop */
@media (min-width: 1024px) {
    .container {
        padding: 0 var(--spacing-2xl);
    }
}

/* Landscape */
@media (max-height: 500px) and (orientation: landscape) {
    h1, h2 { margin-bottom: var(--spacing-sm); }
    .form-group { margin-bottom: var(--spacing-lg); }
}

/* macOS specific */
@media (min-width: 1200px) {
    body {
        background-color: transparent;
    }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    .btn {
        min-height: 48px;
        padding: var(--spacing-md) var(--spacing-lg);
    }
    
    a {
        min-height: 44px;
        min-width: 44px;
        display: inline-flex;
        align-items: center;
    }
}