/* ===== CSS Variables ===== */
:root {
    /* Colors (refreshed palette: teal + indigo + warm accent) */
    --primary: #0ea5a4;
    --primary-dark: #0b8f89;
    --primary-light: #2dd4bf;
    --secondary: #6366f1;
    --accent: #f59e0b;
    --dark: #0f1724;
    --dark-light: #24303a;
    --light: #f8fafc;
    --gray: #6b7280;
    --gray-light: #e6eef2;
    --gray-lighter: #f7fafc;
    --success: #16a34a;
    --warning: #f59e0b;
    --danger: #ef4444;
    --price-color: #0ea5a4;
    --myself: #fff;
    
    /* Typography */
    --font-family: 'Vazirmatn', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 1rem;
    --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;
    --font-size-5xl: 3rem;
    
    /* 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: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    
    /* 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);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --shadow-hover: 0 20px 50px rgba(14, 165, 164, 0.25);
    
    /* 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-xs: 100%;
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;
    --container-2xl: 1536px;
}

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

html {
    font-size: 16px;
    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: 1.7;
    color: var(--dark);
    background-color: var(--light);
    overflow-x: hidden;
    min-height: 100vh;
    -webkit-tap-highlight-color: transparent;
}

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

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

h1 {
    font-size: clamp(var(--font-size-3xl), 5vw, var(--font-size-5xl));
    font-weight: 900;
    letter-spacing: -0.025em;
}

h2 {
    font-size: clamp(var(--font-size-2xl), 4vw, var(--font-size-4xl));
    font-weight: 800;
}

h3 {
    font-size: clamp(var(--font-size-xl), 3vw, var(--font-size-3xl));
    font-weight: 700;
}

h4 {
    font-size: clamp(var(--font-size-lg), 2.5vw, var(--font-size-2xl));
    font-weight: 600;
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--gray);
    line-height: 1.8;
}

.lead {
    font-size: clamp(var(--font-size-lg), 2vw, var(--font-size-xl));
    font-weight: 400;
    color: var(--dark-light);
    line-height: 1.6;
}

svg {
    width: 3.5rem;
    height: 3.5rem;
}

/* ===== Container ===== */
.container {
    width: 100%;
    max-width: var(--container-2xl);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ===== Utilities ===== */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ===== Responsive Design ===== */
/* Large Desktop (≥1400px) */
@media (min-width: 1400px) {
    .container {
        max-width: var(--container-2xl);
    }
}

/* Mobile Portrait (≤575px) */
@media (max-width: 575px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
}

/* Touch Device Optimizations */
@media (hover: none) and (pointer: coarse) {
    /* Add active states for touch devices */
    .nav-link:active {
        background: rgba(14, 165, 164, 0.08);
    }
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
    .header {
        background: white;
        border-bottom: 2px solid black;
    }
    
    .nav-link {
        border: 1px solid black;
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

}