/* ============================================
   DESIGN SYSTEM — Ivan Krišto Portfolio
   ============================================ */

/* CSS Custom Properties */
:root {
    /* Colors */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a28;
    --bg-card: rgba(255, 255, 255, 0.03);
    --bg-card-hover: rgba(255, 255, 255, 0.06);

    --text-primary: #f0f0f5;
    --text-secondary: #a0a0b8;
    --text-muted: #6b6b80;

    --accent-primary: #6c63ff;
    --accent-secondary: #00d4aa;
    --accent-warm: #ff6b35;
    --accent-gradient: linear-gradient(135deg, #6c63ff 0%, #00d4aa 100%);
    --accent-gradient-warm: linear-gradient(135deg, #ff6b35 0%, #ffb347 100%);

    --border-color: rgba(255, 255, 255, 0.06);
    --border-hover: rgba(255, 255, 255, 0.12);

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    /* Spacing */
    --section-padding: 120px;
    --container-width: 1200px;

    /* Transitions */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-spring: 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 16px 64px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(108, 99, 255, 0.15);

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 24px;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    overflow-x: hidden;
}

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

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

ul {
    list-style: none;
}

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

input, textarea {
    font-family: inherit;
}

/* Container */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* Section */
.section {
    padding: var(--section-padding) 0;
    position: relative;
}

/* Text Gradient */
.text-gradient {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Section Header */
.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-tag {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    background: rgba(108, 99, 255, 0.1);
    border: 1px solid rgba(108, 99, 255, 0.2);
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--accent-primary);
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-bottom: 16px;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

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

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 20px 0;
    transition: all var(--transition-smooth);
}

.navbar.scrolled {
    padding: 12px 0;
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 2px;
    letter-spacing: -0.02em;
}

.logo-bracket {
    color: var(--accent-primary);
    font-weight: 300;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    padding: 8px 20px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: 100px;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
}

.nav-link.active {
    background: rgba(108, 99, 255, 0.1);
    color: var(--accent-primary);
}

.nav-cta {
    padding: 10px 24px;
    background: var(--accent-gradient);
    color: white;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: 100px;
    transition: all var(--transition-fast);
    box-shadow: 0 4px 16px rgba(108, 99, 255, 0.3);
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(108, 99, 255, 0.4);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 4px;
    z-index: 1001;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

.nav-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

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

.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 28px;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    cursor: pointer;
    border: none;
    white-space: nowrap;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 4px 20px rgba(108, 99, 255, 0.35);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 32px rgba(108, 99, 255, 0.5);
}

.btn-primary svg {
    transition: transform var(--transition-fast);
}

.btn-primary:hover svg {
    transform: translateX(4px);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-hover);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
    transform: translateY(-2px);
}

.btn-lg {
    padding: 18px 36px;
    font-size: 1.05rem;
}

.btn-full {
    width: 100%;
    justify-content: center;
}

/* ============================================
   PAGE HEADER (for sub-pages)
   ============================================ */

.page-header {
    position: relative;
    min-height: 40vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding-top: 100px;
}

.page-header-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.page-header-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 40px 0;
}

.page-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 900;
    letter-spacing: -0.03em;
    margin-bottom: 12px;
}

.page-subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 500px;
    margin: 0 auto;
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.95rem;
    transition: all var(--transition-fast);
    outline: none;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-muted);
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(108, 99, 255, 0.15);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 80px 0 32px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-brand p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 16px;
    max-width: 320px;
    line-height: 1.6;
}

.footer-social {
    display: flex;
    gap: 12px;
    margin-top: 20px;
}

.footer-social a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.footer-social a:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
    transform: translateY(-2px);
}

.footer-links h4,
.footer-contact h4 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-links a {
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.footer-links a:hover {
    color: var(--accent-primary);
    transform: translateX(4px);
    display: inline-block;
}

.footer-contact ul {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.footer-contact li {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.footer-contact li svg {
    flex-shrink: 0;
    color: var(--accent-primary);
}

.footer-contact a {
    color: var(--text-secondary);
}

.footer-contact a:hover {
    color: var(--accent-primary);
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 24px;
    text-align: center;
}

.footer-bottom p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* ============================================
   CTA SECTION
   ============================================ */

.cta-card {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
    position: relative;
    overflow: hidden;
}

.cta-card::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(108, 99, 255, 0.12) 0%, transparent 70%);
    border-radius: 50%;
}

.cta-content h2 {
    font-size: 1.8rem;
    font-weight: 800;
    margin-bottom: 8px;
    letter-spacing: -0.02em;
}

.cta-content p {
    color: var(--text-secondary);
    font-size: 1.05rem;
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 1024px) {
    :root {
        --section-padding: 80px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 64px;
    }

    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: var(--bg-secondary);
        border-left: 1px solid var(--border-color);
        flex-direction: column;
        align-items: flex-start;
        padding: 100px 32px 32px;
        transition: right var(--transition-smooth);
        gap: 0;
    }

    .nav-menu.open {
        right: 0;
    }

    .nav-link {
        padding: 14px 0;
        font-size: 1.1rem;
        width: 100%;
        border-radius: 0;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-cta {
        display: none;
    }

    .nav-toggle {
        display: flex;
    }

    .section-title {
        font-size: clamp(1.6rem, 5vw, 2.2rem);
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .cta-card {
        flex-direction: column;
        text-align: center;
        padding: 40px 24px;
    }
}

/* ============================================
   ANIMATIONS
   ============================================ */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

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

/* Scroll-triggered animation helper */
[data-aos] {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-aos="fade-up"].aos-animate {
    opacity: 1;
    transform: translateY(0);
}

[data-aos="fade-right"] {
    transform: translateX(-30px);
}

[data-aos="fade-right"].aos-animate {
    opacity: 1;
    transform: translateX(0);
}

[data-aos="fade-left"] {
    transform: translateX(30px);
}

[data-aos="fade-left"].aos-animate {
    opacity: 1;
    transform: translateX(0);
}

/* Glass effect utility */
.glass {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border-color);
}

/* Selection color */
::selection {
    background: var(--accent-primary);
    color: white;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

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