/* ============================================================================
   Enhanced Portfolio Styles with Modern CSS Features
   ============================================================================ */

/* ----------------------------------------------------------------------------
   CSS CUSTOM PROPERTIES (Design Tokens)
   ---------------------------------------------------------------------------- */

:root {
    /* Colors - Light Mode */
    --bg: #f8f9fa;
    --primary: #667eea;
    --primary-alt: #764ba2;
    --accent: #3498db;
    --text-main: #2c3e50;
    --text-muted: #7f8c8d;
    --white: #ffffff;
    --error: #e74c3c;
    --success: #27ae60;
    --warning: #f39c12;
    
    /* Shadows */
    --shadow-soft: 0 5px 20px rgba(0,0,0,0.08);
    --shadow-strong: 0 10px 40px rgba(0,0,0,0.12);
    --shadow-focus: 0 0 0 3px rgba(52, 152, 219, 0.3);
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 15px;
    --radius-lg: 20px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 0.15s ease-out;
    --transition: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Spacing Scale */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* Layout */
    --max-width: 1200px;
    --pad-x: 40px;
    --pad-x-mobile: 20px;
    
    /* Typography Scale */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 2rem;
    --text-4xl: 2.5rem;
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0f172a;
        --text-main: #e2e8f0;
        --text-muted: #94a3b8;
        --white: #1e293b;
        --shadow-soft: 0 5px 20px rgba(0,0,0,0.3);
        --shadow-strong: 0 10px 40px rgba(0,0,0,0.5);
    }
}

/* Reduced Motion Support */
@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;
    }
}

/* ----------------------------------------------------------------------------
   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: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, 
                 Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
    line-height: 1.6;
    color: var(--text-main);
    background: var(--bg);
    overflow-x: hidden;
}

/* ----------------------------------------------------------------------------
   ACCESSIBILITY
   ---------------------------------------------------------------------------- */

/* Screen reader only content */
.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;
}

/* Skip link */
.skip-link {
    position: absolute;
    top: -100px;
    left: 0;
    background: var(--accent);
    color: white;
    padding: var(--space-md);
    text-decoration: none;
    font-weight: 600;
    z-index: 10000;
    border-radius: 0 0 var(--radius-md) 0;
}

.skip-link:focus {
    top: 0;
}

/* Improved focus states */
*:focus {
    outline: none;
}

*:focus-visible {
    outline: 3px solid var(--accent);
    outline-offset: 3px;
    border-radius: var(--radius-sm);
}

/* High contrast focus for interactive elements */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    box-shadow: var(--shadow-focus);
}

/* ----------------------------------------------------------------------------
   TYPOGRAPHY
   ---------------------------------------------------------------------------- */

h1, h2, h3, h4, h5, h6 {
    line-height: 1.2;
    font-weight: 700;
    margin-block-end: var(--space-md);
}

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

p {
    margin-block-end: var(--space-md);
}

a {
    color: inherit;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--accent);
}

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

/* ----------------------------------------------------------------------------
   LAYOUT
   ---------------------------------------------------------------------------- */

.container {
    max-width: var(--max-width);
    margin-inline: auto;
    padding-block: var(--space-3xl);
    padding-inline: var(--pad-x);
}

@media (max-width: 768px) {
    .container {
        padding-block: var(--space-2xl);
        padding-inline: var(--pad-x-mobile);
    }
}

.section-header {
    margin-block-end: var(--space-2xl);
}

.section-title {
    font-size: clamp(28px, 5vw, 36px);
    font-weight: 700;
    color: var(--text-main);
    margin-block-end: var(--space-sm);
}

.section-subtitle {
    font-size: var(--text-lg);
    color: var(--text-muted);
    max-width: 700px;
    line-height: 1.7;
}

/* ----------------------------------------------------------------------------
   HEADER & NAVIGATION
   ---------------------------------------------------------------------------- */

header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--white);
    box-shadow: var(--shadow-soft);
    backdrop-filter: blur(10px);
}

.top-nav {
    max-width: var(--max-width);
    margin-inline: auto;
    padding-block: var(--space-md);
    padding-inline: var(--pad-x);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-lg);
}

.logo {
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--text-main);
    letter-spacing: -0.5px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--space-xl);
}

.nav-menu a {
    color: var(--text-main);
    text-decoration: none;
    font-weight: 600;
    font-size: var(--text-sm);
    padding-block: var(--space-xs);
    border-block-end: 2px solid transparent;
    transition: border-color var(--transition), color var(--transition);
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    inset-block-end: -2px;
    inset-inline-start: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width var(--transition);
}

.nav-menu a:hover::after,
.nav-menu a:focus-visible::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    border: none;
    background: transparent;
    font-size: 22px;
    cursor: pointer;
    padding: var(--space-sm);
    min-width: 44px;
    min-height: 44px;
}

/* Mobile Navigation */
@media (max-width: 768px) {
    .top-nav {
        padding-inline: var(--pad-x-mobile);
    }

    .nav-menu {
        position: absolute;
        inset-block-start: 100%;
        inset-inline: 0;
        max-width: var(--max-width);
        margin-inline: auto;
        padding: var(--space-lg) var(--pad-x-mobile);
        background: var(--white);
        flex-direction: column;
        gap: var(--space-md);
        transform-origin: top;
        transform: scaleY(0);
        opacity: 0;
        pointer-events: none;
        transition: transform var(--transition-fast), opacity var(--transition-fast);
        box-shadow: var(--shadow-strong);
    }

    .nav-menu.open {
        transform: scaleY(1);
        opacity: 1;
        pointer-events: auto;
    }

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

/* ----------------------------------------------------------------------------
   HERO SECTION
   ---------------------------------------------------------------------------- */

.hero-section {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-alt) 100%);
    padding-block: var(--space-3xl);
    padding-inline: var(--pad-x);
    color: var(--white);
    position: relative;
    overflow: hidden;
}

/* Subtle animated background effect */
.hero-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(255,255,255,0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255,255,255,0.08) 0%, transparent 50%);
    animation: heroShine 10s ease-in-out infinite;
}

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

.hero-inner {
    max-width: var(--max-width);
    margin-inline: auto;
    position: relative;
    z-index: 1;
}

.hero-label {
    display: inline-block;
    padding-block: var(--space-sm);
    padding-inline: var(--space-lg);
    border-radius: var(--radius-full);
    background: rgba(255,255,255,0.16);
    backdrop-filter: blur(10px);
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.hero-title {
    font-size: clamp(36px, 8vw, 52px);
    font-weight: 700;
    margin-block-start: var(--space-lg);
    margin-block-end: var(--space-sm);
}

.hero-subtitle {
    font-size: clamp(18px, 3vw, 22px);
    font-weight: 300;
    opacity: 0.95;
    margin-block-end: var(--space-2xl);
}

.stats-bar {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
    gap: var(--space-lg);
}

.stat-box {
    background: rgba(255,255,255,0.16);
    backdrop-filter: blur(10px);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255,255,255,0.2);
    text-align: center;
    transition: transform var(--transition), background var(--transition);
}

.stat-box:hover {
    transform: translateY(-4px);
    background: rgba(255,255,255,0.22);
}

.stat-number {
    font-size: clamp(28px, 5vw, 36px);
    font-weight: 700;
    margin-block-end: var(--space-xs);
}

.stat-label {
    font-size: var(--text-sm);
    font-weight: 500;
    opacity: 0.9;
}

/* ----------------------------------------------------------------------------
   CARDS
   ---------------------------------------------------------------------------- */

.card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: var(--space-2xl);
    box-shadow: var(--shadow-soft);
    transition: transform var(--transition), box-shadow var(--transition);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-strong);
}

.card-title {
    font-size: var(--text-xl);
    font-weight: 700;
    margin-block-end: var(--space-md);
    color: var(--text-main);
}

/* Experience Cards */
.experience-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 340px), 1fr));
    gap: var(--space-lg);
}

.experience-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition);
}

.experience-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-strong);
}

.card-header {
    padding: var(--space-lg) var(--space-xl);
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-alt) 100%);
    color: var(--white);
}

.card-company {
    font-size: var(--text-sm);
    opacity: 0.95;
    margin-block-start: var(--space-xs);
}

.card-date {
    margin-block-start: var(--space-md);
    display: inline-block;
    padding-block: var(--space-xs);
    padding-inline: var(--space-md);
    border-radius: var(--radius-full);
    background: rgba(255,255,255,0.16);
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.card-content {
    padding: var(--space-lg) var(--space-xl);
}

.achievement-list {
    list-style: none;
}

.achievement-list li {
    position: relative;
    padding-block: var(--space-md);
    padding-inline-start: var(--space-xl);
    border-block-end: 1px solid #ecf0f1;
    font-size: var(--text-sm);
    color: #555;
    transition: 
        background var(--transition),
        color var(--transition),
        padding-inline-start var(--transition);
}

.achievement-list li:last-child {
    border-block-end: none;
}

.achievement-list li::before {
    content: "→";
    position: absolute;
    inset-inline-start: var(--space-sm);
    inset-block-start: var(--space-md);
    color: var(--accent);
    font-weight: 700;
}

.achievement-list li:hover {
    background: #f8f9fa;
    color: var(--text-main);
    padding-inline-start: calc(var(--space-xl) + var(--space-xs));
}

/* ----------------------------------------------------------------------------
   SKILLS
   ---------------------------------------------------------------------------- */

.skills-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr));
    gap: var(--space-lg);
}

.skill-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-soft);
    transition: transform var(--transition), box-shadow var(--transition);
}

.skill-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-strong);
}

.skill-header {
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--text-main);
    padding-block-end: var(--space-md);
    border-block-end: 3px solid var(--accent);
    margin-block-end: var(--space-lg);
}

.skill-pills {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
}

.skill-pill {
    display: inline-block;
    padding-block: var(--space-sm);
    padding-inline: var(--space-md);
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-alt) 100%);
    color: var(--white);
    font-size: var(--text-sm);
    font-weight: 600;
    transition: transform var(--transition), box-shadow var(--transition);
}

.skill-pill:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 18px rgba(102,126,234,0.4);
}

/* ----------------------------------------------------------------------------
   DASHBOARD / DEMO
   ---------------------------------------------------------------------------- */

.demo-section {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: var(--space-2xl) var(--space-xl);
    box-shadow: var(--shadow-strong);
}

.demo-header {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: var(--space-lg);
    flex-wrap: wrap;
    margin-block-end: var(--space-2xl);
}

.demo-title {
    font-size: clamp(20px, 4vw, 26px);
    font-weight: 700;
    color: var(--text-main);
}

.demo-subtitle {
    font-size: var(--text-sm);
    color: var(--text-muted);
    margin-block-start: var(--space-xs);
}

.demo-controls {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
}

.demo-btn {
    border: none;
    border-radius: var(--radius-sm);
    padding-block: var(--space-sm);
    padding-inline: var(--space-md);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--white);
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-alt) 100%);
    cursor: pointer;
    min-height: 44px;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.demo-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 16px rgba(102,126,234,0.4);
}

.demo-btn.active {
    background: var(--text-main);
    box-shadow: 0 5px 16px rgba(44,62,80,0.4);
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 230px), 1fr));
    gap: var(--space-lg);
    margin-block-end: var(--space-2xl);
}

.metric-card {
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-alt) 100%);
    color: var(--white);
    transition: transform var(--transition), box-shadow var(--transition);
}

.metric-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(102,126,234,0.4);
}

@keyframes pulse {
    0% { transform: scale(1); }
    40% { transform: scale(1.03); }
    100% { transform: scale(1); }
}

.metric-card.pulse {
    animation: pulse 0.5s ease-out;
}

.metric-label {
    font-size: var(--text-xs);
    text-transform: uppercase;
    letter-spacing: 0.8px;
    margin-block-end: var(--space-sm);
    opacity: 0.9;
    font-weight: 600;
}

.metric-value {
    font-size: clamp(24px, 5vw, 30px);
    font-weight: 700;
    margin-block-end: var(--space-xs);
}

.metric-change {
    font-size: var(--text-sm);
    font-weight: 600;
    opacity: 0.9;
}

/* ----------------------------------------------------------------------------
   FOOTER
   ---------------------------------------------------------------------------- */

footer {
    background: #2c3e50;
    color: var(--white);
    padding-block: var(--space-2xl);
    padding-inline: var(--space-lg);
    margin-block-start: var(--space-3xl);
    text-align: center;
}

footer p {
    font-size: var(--text-sm);
    opacity: 0.9;
    margin-block-end: var(--space-xs);
}

/* ----------------------------------------------------------------------------
   UTILITY CLASSES
   ---------------------------------------------------------------------------- */

.text-center { text-align: center; }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.gap-4 { gap: var(--space-md); }

/* ----------------------------------------------------------------------------
   PRINT STYLES
   ---------------------------------------------------------------------------- */

@media print {
    header,
    footer,
    .nav-toggle,
    .demo-controls {
        display: none;
    }

    body {
        color: #000;
        background: #fff;
    }

    a {
        text-decoration: underline;
    }
}