/* ============================================
   BASE STYLES & RESET
   ============================================ */

/* Modern CSS Reset */
*,
*::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;
    text-rendering: optimizeLegibility;
}

body {
    font-family: var(--font-family);
    font-weight: var(--font-normal);
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* Background gradient overlay */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(ellipse at 20% 20%, rgba(255, 107, 107, 0.03) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(167, 139, 250, 0.03) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

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

h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-bold);
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-3xl); }
h4 { font-size: var(--text-2xl); }
h5 { font-size: var(--text-xl); }
h6 { font-size: var(--text-lg); }

p {
    margin-bottom: 1em;
}

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

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

/* ============================================
   IMAGES & MEDIA
   ============================================ */

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

img {
    object-fit: cover;
}

/* Lazy loading placeholder */
img[loading="lazy"] {
    background: linear-gradient(
        90deg,
        var(--bg-tertiary) 0%,
        var(--bg-card-hover) 50%,
        var(--bg-tertiary) 100%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ============================================
   BUTTONS BASE
   ============================================ */

button {
    font-family: inherit;
    font-size: inherit;
    border: none;
    background: none;
    cursor: pointer;
    outline: none;
}

button:disabled {
    cursor: not-allowed;
    opacity: 0.5;
}

/* ============================================
   FORMS
   ============================================ */

input,
textarea,
select {
    font-family: inherit;
    font-size: inherit;
    border: none;
    outline: none;
    background: var(--bg-elevated);
    color: var(--text-primary);
}

input::placeholder,
textarea::placeholder {
    color: var(--text-tertiary);
}

/* ============================================
   SCROLLBAR - CUSTOM
   ============================================ */

::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

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

::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: var(--radius-full);
    border: 2px solid var(--bg-primary);
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, var(--primary-light) 0%, var(--primary) 100%);
}

/* Firefox */
* {
    scrollbar-width: thin;
    scrollbar-color: var(--primary) var(--bg-primary);
}

/* ============================================
   SELECTION
   ============================================ */

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

::-moz-selection {
    background: var(--primary);
    color: white;
}

/* ============================================
   UTILITY CLASSES
   ============================================ */

.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.container-narrow {
    max-width: var(--container-narrow);
}

.container-wide {
    max-width: var(--container-wide);
}

/* Flex utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* Grid utilities */
.grid { display: grid; }

/* Text utilities */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-ellipsis {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Visibility */
.hidden { display: none !important; }
.invisible { visibility: hidden; }
.visible { visibility: visible; }

/* Position */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

/* Z-index */
.z-10 { z-index: 10; }
.z-20 { z-index: 20; }
.z-30 { z-index: 30; }
.z-40 { z-index: 40; }
.z-50 { z-index: 50; }

/* Overflow */
.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-scroll { overflow: scroll; }

/* ============================================
   ACCESSIBILITY
   ============================================ */

.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;
}

:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* Skip link */
.skip-link {
    position: absolute;
    top: -100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: white;
    padding: var(--space-3) var(--space-6);
    border-radius: var(--radius-md);
    z-index: var(--z-notification);
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: var(--space-4);
}

/* ============================================
   APP STRUCTURE - FIXED HEADER OFFSET
   ============================================ */

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.main-content {
    flex: 1;
    padding-top: calc(var(--header-height) + var(--space-6));
}

@media (max-width: 768px) {
    .main-content {
        padding-top: calc(var(--header-height-mobile) + var(--space-4));
    }
}

/* ============================================
   LOADING SCREEN
   ============================================ */

.loading-screen {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
    transition: opacity var(--transition-slow), visibility var(--transition-slow);
}

.loading-screen.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.loading-logo {
    text-align: center;
}

.loading-spinner {
    width: 60px;
    height: 60px;
    border: 3px solid var(--bg-tertiary);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto var(--space-6);
}

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

.loading-text {
    font-size: var(--text-2xl);
    font-weight: var(--font-bold);
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}