/* ==========================================================================
   BASE STYLES & RESET
   Muhammad Saad Qasim - Portfolio 2026
   ========================================================================== */

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.65;
    overflow-x: hidden;
    min-height: 100vh;
    position: relative;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Background Ambient Lighting Mesh */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: 
        radial-gradient(circle at 15% 15%, var(--primary-glow) 0%, transparent 45%),
        radial-gradient(circle at 85% 65%, var(--secondary-glow) 0%, transparent 50%),
        radial-gradient(circle at 50% 90%, rgba(168, 85, 247, 0.15) 0%, transparent 40%);
    pointer-events: none;
    z-index: -1;
    opacity: 0.8;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-main);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    border: 2px solid var(--bg-main);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}

/* Selection */
::selection {
    background: var(--primary);
    color: #ffffff;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.25;
    color: var(--text-main);
    letter-spacing: -0.02em;
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 3.5vw, 2.75rem); }
h3 { font-size: clamp(1.4rem, 2.2vw, 1.85rem); }
h4 { font-size: 1.25rem; }
p { color: var(--text-muted); font-size: 1.05rem; }

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

a:hover {
    color: var(--secondary-light);
}

code, pre, .font-mono {
    font-family: var(--font-mono);
}

/* Container */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Section Wrapper */
section {
    padding: 6.5rem 0;
    position: relative;
}

.section-header {
    text-align: center;
    max-width: 720px;
    margin: 0 auto 3.5rem auto;
}

.section-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.35rem 0.9rem;
    background: rgba(99, 102, 241, 0.12);
    border: 1px solid var(--border-glow);
    border-radius: var(--radius-full);
    color: var(--primary-light);
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-bottom: 1rem;
}

.section-title {
    margin-bottom: 1rem;
    position: relative;
}

.section-subtitle {
    font-size: 1.15rem;
    color: var(--text-muted);
}

/* Text Gradients */
.text-gradient {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.text-gradient-accent {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

/* Glass Panels */
.glass-panel {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.glass-card {
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
}

.glass-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-glow);
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow);
}

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