/* ==========================================================================
   DESIGN SYSTEM & VARIABLES
   ========================================================================== */

:root {
    /* Font Families */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-mono: 'Fira Code', monospace;

    /* Animation Speeds */
    --transition-speed: 0.3s;
    --transition-ease: cubic-bezier(0.4, 0, 0.2, 1);
}

/* Light Theme Variables */
[data-theme="light"] {
    --bg-primary: #f8fafc;
    /* slate-50 */
    --bg-secondary: #f1f5f9;
    /* slate-100 */
    --text-primary: #0f172a;
    /* slate-900 */
    --text-secondary: #475569;
    /* slate-600 */
    --accent: #0369a1;
    /* sky-700 (darker for 4.5:1 WCAG contrast) */
    --accent-hover: #025a8b;
    /* sky-800 */
    --border-color: #cbd5e1;
    /* slate-300 */
    --card-bg: #ffffff;
    --shadow: 0 4px 6px -1px rgba(15, 23, 42, 0.05), 0 2px 4px -2px rgba(15, 23, 42, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, 0.05), 0 4px 6px -4px rgba(15, 23, 42, 0.05);

    /* Components Specific */
    --nav-bg: rgba(248, 250, 252, 0.85);
    --toggler-filter: none;
    --btn-primary-text: #ffffff;
    /* white text for dark sky-700 bg */
}

/* Dark Theme Variables */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    /* slate-900 */
    --bg-secondary: #1e293b;
    /* slate-800 */
    --text-primary: #f8fafc;
    /* slate-50 */
    --text-secondary: #cbd5e1;
    /* slate-300 (lightened for 4.5:1 WCAG contrast on slate-800 card bg) */
    --accent: #38bdf8;
    /* sky-400 */
    --accent-hover: #7dd3fc;
    /* sky-300 */
    --border-color: #334155;
    /* slate-700 */
    --card-bg: #1e293b;
    /* slate-800 */
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -4px rgba(0, 0, 0, 0.3);

    /* Components Specific */
    --nav-bg: rgba(15, 23, 42, 0.85);
    --toggler-filter: invert(1) grayscale(1) brightness(2);
    --btn-primary-text: #0f172a;
    /* dark slate-900 text for light sky-400 bg */
}

/* Global scroll behavior */
html {
    scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }
}

/* ==========================================================================
   GLOBAL RULES & BASE RESETS
   ========================================================================== */

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    transition: background-color var(--transition-speed) var(--transition-ease),
        color var(--transition-speed) var(--transition-ease),
        border-color var(--transition-speed) var(--transition-ease);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    color: var(--text-primary);
    transition: color var(--transition-speed) var(--transition-ease);
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color var(--transition-speed) var(--transition-ease);
}

a:hover,
a:focus {
    color: var(--accent-hover);
    text-decoration: none;
}

/* Interactive elements focus states */
a:focus-visible,
button:focus-visible,
.nav-link:focus-visible,
.btn:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 4px;
    border-radius: 4px;
}

/* ==========================================================================
   NAVIGATION
   ========================================================================== */

.header-nav {
    border-bottom: 1px solid var(--border-color);
    background-color: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    transition: background-color var(--transition-speed) var(--transition-ease),
        border-color var(--transition-speed) var(--transition-ease);
}

.navbar-custom {
    transition: padding var(--transition-speed) var(--transition-ease);
}

.navbar-custom .navbar-brand {
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.4rem;
    color: var(--text-primary);
    letter-spacing: -0.025em;
    display: flex;
    align-items: center;
    transition: color var(--transition-speed) var(--transition-ease);
}

.brand-code-bracket {
    color: var(--accent);
    font-family: var(--font-mono);
    font-weight: 600;
    transition: color var(--transition-speed) var(--transition-ease);
}

.brand-name {
    margin: 0 0.15rem;
}

.navbar-custom .nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition-speed) var(--transition-ease);
}

.navbar-custom .nav-link:hover,
.navbar-custom .nav-link:focus,
.navbar-custom .nav-link.active {
    color: var(--accent);
}

/* Mobile Toggler */
.navbar-toggler {
    border-color: var(--border-color);
    padding: 0.4rem 0.6rem;
    transition: border-color var(--transition-speed) var(--transition-ease);
}

.navbar-toggler-icon {
    filter: var(--toggler-filter);
    transition: filter var(--transition-speed) var(--transition-ease);
}

/* Theme Toggle Button styling */
.btn-theme-toggle {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-speed) var(--transition-ease);
}

.btn-theme-toggle:hover {
    color: var(--accent);
    border-color: var(--accent);
    background-color: var(--bg-secondary);
}

/* ==========================================================================
   SECTIONS & LAYOUT (PLACEHOLDERS)
   ========================================================================== */

/* ==========================================================================
   SECTIONS & LAYOUT (CUSTOMIZED)
   ========================================================================== */

.section-hero {
    min-height: 85vh;
    padding: 120px 0 80px 0;
    transition: background-color var(--transition-speed) var(--transition-ease);
}

.hero-pretitle {
    font-family: var(--font-mono);
    color: var(--accent);
    font-size: 1.05rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    display: block;
    letter-spacing: 0.05em;
}

.hero-title {
    font-size: clamp(2.5rem, 5.5vw, 4.25rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 0.8rem;
    letter-spacing: -0.03em;
}

.hero-tagline {
    font-size: clamp(1.2rem, 2vw, 1.6rem);
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 1.5rem;
}

.hero-location {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.hero-cta {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 2rem;
}

/* Custom Buttons matching palettes */
.btn-primary-custom {
    background-color: var(--accent);
    color: var(--btn-primary-text) !important;
    border: 1px solid var(--accent);
    font-weight: 600;
    font-size: 0.95rem;
    padding: 0.75rem 1.6rem;
    border-radius: 8px;
    transition: all var(--transition-speed) var(--transition-ease);
}

.btn-primary-custom:hover {
    background-color: var(--accent-hover);
    border-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(14, 165, 233, 0.2);
}

.btn-secondary-custom {
    background-color: transparent;
    color: var(--text-primary) !important;
    border: 1px solid var(--border-color);
    font-weight: 600;
    font-size: 0.95rem;
    padding: 0.75rem 1.6rem;
    border-radius: 8px;
    transition: all var(--transition-speed) var(--transition-ease);
}

.btn-secondary-custom:hover {
    background-color: var(--bg-secondary);
    border-color: var(--text-secondary);
    transform: translateY(-2px);
}

/* Social links list */
.hero-socials {
    display: flex;
    gap: 1.25rem;
    align-items: center;
}

.social-link {
    font-size: 1.4rem;
    color: var(--text-secondary);
    transition: all var(--transition-speed) var(--transition-ease);
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.social-link:hover {
    color: var(--accent);
    transform: translateY(-2px);
}

/* Hero Image & Decorative Border */
.hero-img-wrapper {
    position: relative;
    max-width: 360px;
    margin: 0 auto;
}

.hero-img-wrapper::before {
    content: '';
    position: absolute;
    top: 15px;
    left: 15px;
    right: -15px;
    bottom: -15px;
    border: 2px solid var(--accent);
    border-radius: 16px;
    z-index: 1;
    transition: all var(--transition-speed) var(--transition-ease);
}

.hero-img-wrapper:hover::before {
    top: 8px;
    left: 8px;
    right: -8px;
    bottom: -8px;
}

.hero-img {
    position: relative;
    z-index: 2;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    background-color: var(--card-bg);
    width: 100%;
    height: auto;
}

/* Section Headings */
.section-padding {
    padding: 100px 0;
    transition: background-color var(--transition-speed) var(--transition-ease),
        border-color var(--transition-speed) var(--transition-ease);
}

.section-title {
    font-size: 2.15rem;
    font-weight: 800;
    margin-bottom: 2.5rem;
    position: relative;
    display: inline-block;
    padding-bottom: 0.6rem;
    letter-spacing: -0.02em;
}

.section-title::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 50px;
    height: 4px;
    background-color: var(--accent);
    border-radius: 2px;
}

/* About Section Typography */
.about-text {
    font-size: 1.05rem;
    line-height: 1.75;
    color: var(--text-secondary);
    margin-bottom: 1.25rem;
}

/* Skills Cards & Badges */
.skills-container {
    margin-top: 1rem;
}

.skill-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    height: 100%;
    box-shadow: var(--shadow);
    transition: all var(--transition-speed) var(--transition-ease);
}

.skill-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent);
}

.skill-card-title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 1.2rem;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    color: var(--text-primary);
}

.skill-card-title i {
    color: var(--accent);
    font-size: 1.25rem;
}

.skill-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-badge {
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 500;
    padding: 0.4rem 0.75rem;
    border-radius: 6px;
    transition: all var(--transition-speed) var(--transition-ease);
}

.skill-badge:hover {
    background-color: var(--accent);
    color: var(--btn-primary-text);
    border-color: var(--accent);
    transform: translateY(-1px);
}

/* Background striping for visual hierarchy */
#hero,
#skills,
#experience,
#projects {
    background-color: var(--bg-primary);
}

#about,
#featured-work,
#education,
#contact {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

/* Footer style */
footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    transition: background-color var(--transition-speed) var(--transition-ease),
        border-top var(--transition-speed) var(--transition-ease),
        color var(--transition-speed) var(--transition-ease);
}

/* ==========================================================================
   TIMELINE (EXPERIENCE & EDUCATION)
   ========================================================================== */

.timeline {
    position: relative;
    padding-left: 35px;
    margin-top: 1rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 8px;
    top: 10px;
    bottom: 10px;
    width: 2px;
    background-color: var(--border-color);
    transition: background-color var(--transition-speed) var(--transition-ease);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-marker {
    position: absolute;
    left: -35px;
    top: 8px;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background-color: var(--bg-primary);
    border: 3px solid var(--accent);
    z-index: 2;
    transition: all var(--transition-speed) var(--transition-ease);
}

.timeline-item:hover .timeline-marker {
    background-color: var(--accent);
    transform: scale(1.2);
    box-shadow: 0 0 0 4px rgba(14, 165, 233, 0.15);
}

.timeline-content {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.75rem;
    box-shadow: var(--shadow);
    transition: all var(--transition-speed) var(--transition-ease);
}

.timeline-content:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent);
}

.timeline-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.timeline-company {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 0.5rem;
    font-family: var(--font-heading);
}

.timeline-meta {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-family: var(--font-mono);
    margin-bottom: 1rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.timeline-meta span {
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.border-color {
    border-color: var(--border-color) !important;
}

@media (max-width: 767.98px) {
    .timeline {
        padding-left: 0;
    }

    .timeline::before {
        display: none;
    }

    .timeline-marker {
        display: none;
    }

    .timeline-content {
        padding: 1.25rem;
    }
}

/* ==========================================================================
   PROJECT CARDS & HIGHLIGHTS
   ========================================================================== */

.project-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.75rem;
    box-shadow: var(--shadow);
    transition: all var(--transition-speed) var(--transition-ease);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent);
}

.project-card-featured {
    border-left: 4px solid var(--accent) !important;
}

.bg-accent-soft {
    background-color: rgba(14, 165, 233, 0.1);
    color: var(--accent) !important;
}

[data-theme="dark"] .bg-accent-soft {
    background-color: rgba(56, 189, 248, 0.15);
    color: #38bdf8 !important;
}

/* Form Styling overrides for themes */
.form-control {
    color: var(--text-primary) !important;
    background-color: var(--bg-primary) !important;
    border-color: var(--border-color) !important;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    transition: background-color var(--transition-speed) var(--transition-ease),
        border-color var(--transition-speed) var(--transition-ease),
        color var(--transition-speed) var(--transition-ease);
}

.form-control:focus {
    color: var(--text-primary) !important;
    background-color: var(--bg-primary) !important;
    border-color: var(--accent) !important;
    box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.15) !important;
    outline: none;
}

.form-control::placeholder {
    color: var(--text-secondary) !important;
    opacity: 0.85 !important;
}

.icon-box {
    color: var(--accent);
    transition: all var(--transition-speed) var(--transition-ease);
}

/* ==========================================================================
   GLOBAL CARD STYLING & UTILITY CLASSES
   ========================================================================== */

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    transition: background-color var(--transition-speed) var(--transition-ease),
        border-color var(--transition-speed) var(--transition-ease),
        box-shadow var(--transition-speed) var(--transition-ease);
}

/* Theme Utility Overrides */
.bg-theme-primary {
    background-color: var(--bg-primary) !important;
}

.bg-theme-secondary {
    background-color: var(--bg-secondary) !important;
}

.text-theme-primary {
    color: var(--text-primary) !important;
}

.text-theme-secondary {
    color: var(--text-secondary) !important;
}

.text-accent {
    color: var(--accent) !important;
}

/* ==========================================================================
   RESPONSIVE DESIGN ADAPTATIONS (Desktop & Tablet)
   ========================================================================== */

@media (max-width: 991.98px) {

    /* Make theme toggle look cleaner in mobile menu */
    .btn-theme-toggle {
        border-radius: 6px;
        width: auto;
        height: auto;
        padding: 0.5rem 1rem;
        display: inline-flex;
        align-items: center;
        justify-content: flex-start;
        width: 100%;
        border-color: var(--border-color);
    }
}

/* ==========================================================================
   SCROLL REVEAL ANIMATIONS
   ========================================================================== */

.reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.4s cubic-bezier(0.25, 1, 0.5, 1),
        transform 0.4s cubic-bezier(0.25, 1, 0.5, 1);
    will-change: opacity, transform;
}

.reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
    .reveal {
        opacity: 1 !important;
        transform: none !important;
        transition: none !important;
    }
}


.social-card {
    width: 120px;
    height: 120px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 18px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--text-primary);
    transition: .3s ease;
}

.social-card i {
    font-size: 2rem;
    color: var(--accent-color);
}

.social-card span {
    font-size: .95rem;
    font-weight: 600;
}

.social-card:hover {
    transform: translateY(-8px);
    border-color: var(--accent-color);
    box-shadow: 0 10px 25px rgba(0, 0, 0, .15);
}

.social-card:hover i {
    transform: scale(1.15);
}