/* ========================================
   Navigation - Clean Transparent Style
======================================== */
.navbar {
    position: fixed !important;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: var(--space-md) 0;
    background: transparent;
    border-bottom: none;
    box-shadow: none;
    transition: all 0.3s ease;
}

[data-theme="light"] .navbar {
    background: transparent;
    border-bottom: none;
    box-shadow: none;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.nav-logo img {
    height: 36px;
    width: auto;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.logo-dot {
    display: none;
}

/* Navigation Menu - Clean Minimal Style */
.nav-menu {
    display: flex;
    align-items: center;
    gap: 2px;
    position: relative;
    padding: 6px 8px;
    background: transparent;
    border: none;
    border-radius: 50px;
}

/* Light Theme Menu */
[data-theme="light"] .nav-menu {
    background: transparent;
    border: none;
}

/* Sliding Indicator - Border Only */
.nav-indicator {
    position: absolute;
    background: transparent;
    border: 1.5px solid rgba(255, 255, 255, 0.35);
    border-radius: 50px;
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.1);
    pointer-events: none;
    z-index: 0;
    opacity: 0;
    transition:
        left 0.4s cubic-bezier(0.34, 1.56, 0.64, 1),
        width 0.4s cubic-bezier(0.34, 1.56, 0.64, 1),
        opacity 0.3s ease,
        transform 0.2s ease;
}

.nav-indicator.active {
    opacity: 1;
}

/* Morphing animation on move */
.nav-indicator.morphing {
    transform: scaleX(1.06) scaleY(0.9);
}

/* Light Theme Indicator - Dark Border Only */
[data-theme="light"] .nav-indicator {
    background: transparent;
    border: 1.5px solid rgba(0, 0, 0, 0.25);
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
}

/* Nav Link with Magnifying Effect */
.nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: 10px 18px;
    position: relative;
    z-index: 1;
    border-radius: 50px;
    transition:
        color 0.3s ease,
        transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1),
        font-size 0.3s ease,
        text-shadow 0.3s ease;
    transform-origin: center bottom;
}

/* Magnifying Glass Effect on Hover - macOS Dock Style */
.nav-link:hover {
    color: var(--text-primary);
    transform: scale(1.12) translateY(-2px);
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

/* Scale neighbors slightly - dock effect */
.nav-link:hover+.nav-link {
    transform: scale(1.05);
}

.nav-link:has(+ .nav-link:hover) {
    transform: scale(1.05);
}

.nav-link.active {
    color: var(--text-primary);
    font-weight: 600;
}

/* Light Theme */
[data-theme="light"] .nav-link:hover,
[data-theme="light"] .nav-link.active {
    color: var(--text-primary);
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.nav-cta {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-lg);
    background: var(--accent);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    transition: var(--transition-base);
}

.nav-cta:hover {
    background: var(--accent-dark);
    transform: translateY(-2px);
}

/* Mobile Nav Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-sm);
}

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

@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: calc(100% + 10px);
        left: 50%;
        transform: translateX(-50%);
        right: auto;
        width: calc(100% - 40px);
        max-width: 400px;
        flex-direction: column;
        padding: var(--space-md);
        background: rgba(15, 15, 25, 0.98);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        border: 1px solid rgba(255, 255, 255, 0.1);
        border-radius: var(--radius-lg);
        box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-link {
        width: 100%;
        text-align: center;
        padding: 14px 20px;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-cta {
        display: none;
    }
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

/* Theme Toggle - Liquid Glass Orb */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: linear-gradient(135deg,
            rgba(255, 255, 255, 0.1) 0%,
            rgba(255, 255, 255, 0.03) 100%);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-secondary);
    font-size: 1.25rem;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow:
        0 4px 15px rgba(0, 0, 0, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
    position: relative;
    overflow: hidden;
}

/* Shine Effect */
.theme-toggle::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 50%;
    background: linear-gradient(180deg,
            rgba(255, 255, 255, 0.2) 0%,
            transparent 100%);
    border-radius: 50% 50% 0 0;
    pointer-events: none;
}

.theme-toggle:hover {
    background: linear-gradient(135deg,
            rgba(255, 255, 255, 0.15) 0%,
            rgba(255, 255, 255, 0.05) 100%);
    border-color: rgba(99, 102, 241, 0.3);
    color: var(--accent);
    transform: rotate(15deg) scale(1.1);
    box-shadow:
        0 8px 25px rgba(0, 0, 0, 0.15),
        0 0 30px rgba(99, 102, 241, 0.15),
        inset 0 1px 1px rgba(255, 255, 255, 0.2);
}

[data-theme="light"] .theme-toggle {
    background: linear-gradient(135deg,
            rgba(255, 255, 255, 0.8) 0%,
            rgba(255, 255, 255, 0.5) 100%);
    border: 1px solid rgba(255, 255, 255, 0.7);
}

/* Language Toggle - Premium Glassmorphism Lens Switch */
.lang-switch {
    position: relative;
    display: flex;
    align-items: center;
    width: 68px;
    height: 34px;
    background: linear-gradient(135deg,
            rgba(255, 255, 255, 0.12) 0%,
            rgba(255, 255, 255, 0.05) 50%,
            rgba(255, 255, 255, 0.12) 100%);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-full);
    cursor: pointer;
    padding: 0 4px;
    transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    box-shadow:
        0 4px 20px rgba(0, 0, 0, 0.15),
        0 0 0 1px rgba(255, 255, 255, 0.05),
        inset 0 1px 1px rgba(255, 255, 255, 0.15),
        inset 0 -1px 1px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

/* Frosted glass inner shine */
.lang-switch::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
            transparent,
            rgba(255, 255, 255, 0.15),
            transparent);
    transition: left 0.5s ease;
}

.lang-switch:hover::before {
    left: 100%;
}

.lang-switch:hover {
    border-color: rgba(99, 102, 241, 0.4);
    transform: scale(1.02);
    box-shadow:
        0 6px 25px rgba(0, 0, 0, 0.2),
        0 0 25px rgba(99, 102, 241, 0.15),
        inset 0 1px 2px rgba(255, 255, 255, 0.2);
}

/* Light Theme - Glassmorphism */
[data-theme="light"] .lang-switch {
    background: linear-gradient(135deg,
            rgba(255, 255, 255, 0.7) 0%,
            rgba(255, 255, 255, 0.4) 50%,
            rgba(255, 255, 255, 0.7) 100%);
    border: 1px solid rgba(99, 102, 241, 0.25);
    box-shadow:
        0 4px 20px rgba(99, 102, 241, 0.1),
        0 0 0 1px rgba(255, 255, 255, 0.5),
        inset 0 1px 2px rgba(255, 255, 255, 0.9),
        inset 0 -1px 1px rgba(0, 0, 0, 0.05);
}

[data-theme="light"] .lang-switch:hover {
    border-color: rgba(99, 102, 241, 0.4);
    box-shadow:
        0 6px 25px rgba(99, 102, 241, 0.15),
        0 0 20px rgba(99, 102, 241, 0.1),
        inset 0 1px 2px rgba(255, 255, 255, 0.95);
}

/* Lens Thumb - Refractive Glass Ball */
.lang-switch-thumb {
    position: absolute;
    left: 4px;
    width: 26px;
    height: 26px;
    background: linear-gradient(145deg,
            rgba(99, 102, 241, 1) 0%,
            rgba(168, 85, 247, 0.9) 50%,
            rgba(99, 102, 241, 0.95) 100%);
    border-radius: 50%;
    transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    box-shadow:
        0 3px 8px rgba(99, 102, 241, 0.4),
        0 0 15px rgba(99, 102, 241, 0.2),
        inset 0 2px 3px rgba(255, 255, 255, 0.3),
        inset 0 -2px 3px rgba(0, 0, 0, 0.1);
}

/* Lens refraction highlight */
.lang-switch-thumb::before {
    content: '';
    position: absolute;
    top: 4px;
    left: 5px;
    width: 8px;
    height: 8px;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 50%;
    filter: blur(1px);
}

/* Thumb position when VI selected */
.lang-switch.vi .lang-switch-thumb {
    transform: translateX(34px);
}

.lang-switch-labels {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 4px;
    pointer-events: none;
    z-index: 1;
    box-sizing: border-box;
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--text-tertiary);
}

.lang-switch-labels span {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 24px;
    height: 100%;
    transition: color 0.3s ease;
}

.lang-switch.en .lang-switch-labels span:first-child,
.lang-switch.vi .lang-switch-labels span:last-child {
    color: white;
}

[data-theme="light"] .lang-switch.en .lang-switch-labels span:first-child,
[data-theme="light"] .lang-switch.vi .lang-switch-labels span:last-child {
    color: white;
}

/* Contact Form */
.contact-form-section {
    padding-bottom: var(--space-4xl);
}

/* Form Container - Liquid Glass */
.form-container {
    max-width: 600px;
    margin: 0 auto;
    padding: var(--space-2xl);
    background: linear-gradient(145deg,
            rgba(255, 255, 255, 0.08) 0%,
            rgba(255, 255, 255, 0.02) 100%);
    backdrop-filter: blur(40px) saturate(180%);
    -webkit-backdrop-filter: blur(40px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.12);
    box-shadow:
        0 8px 32px rgba(0, 0, 0, 0.12),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    position: relative;
    overflow: hidden;
}

.form-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 50%;
    background: linear-gradient(180deg,
            rgba(255, 255, 255, 0.1) 0%,
            transparent 100%);
    pointer-events: none;
}

[data-theme="light"] .form-container {
    background: linear-gradient(145deg,
            rgba(255, 255, 255, 0.9) 0%,
            rgba(255, 255, 255, 0.6) 100%);
    border: 1px solid rgba(255, 255, 255, 0.8);
}

.form-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-xl);
    text-align: center;
    position: relative;
    z-index: 1;
}

.form-group {
    margin-bottom: var(--space-lg);
    position: relative;
    z-index: 1;
}

.form-label {
    display: block;
    margin-bottom: var(--space-xs);
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

/* Form Input - Liquid Glass */
.form-input {
    width: 100%;
    padding: var(--space-md);
    background: linear-gradient(135deg,
            rgba(255, 255, 255, 0.08) 0%,
            rgba(255, 255, 255, 0.02) 100%);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: var(--radius-lg);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.form-input:focus {
    outline: none;
    border-color: rgba(99, 102, 241, 0.5);
    background: linear-gradient(135deg,
            rgba(255, 255, 255, 0.12) 0%,
            rgba(255, 255, 255, 0.04) 100%);
    box-shadow:
        0 0 0 4px rgba(99, 102, 241, 0.15),
        0 0 30px rgba(99, 102, 241, 0.1),
        inset 0 1px 1px rgba(255, 255, 255, 0.1);
}

[data-theme="light"] .form-input {
    background: linear-gradient(135deg,
            rgba(255, 255, 255, 0.7) 0%,
            rgba(255, 255, 255, 0.4) 100%);
    border: 1px solid rgba(255, 255, 255, 0.6);
}

[data-theme="light"] .form-input:focus {
    box-shadow:
        0 0 0 4px rgba(99, 102, 241, 0.1),
        0 0 20px rgba(99, 102, 241, 0.08);
}

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

.btn-submit {
    width: 100%;
    justify-content: center;
    margin-top: var(--space-sm);
}

/* ========================================
   Footer
======================================== */
.footer {
    /* Reduced padding as requested: "shorten the empty space" */
    padding: var(--space-lg) 0 var(--space-md);
    background: linear-gradient(to top, rgba(0, 0, 0, 0.9), rgba(0, 0, 0, 0.4));
    position: relative;
    overflow: hidden;
}

/* Continuous Neon LED Border */
.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg,
            var(--accent-primary),
            #ffffff,
            var(--accent-primary),
            #ffffff,
            var(--accent-primary));
    background-size: 200% auto;
    animation: neon-flow 3s linear infinite;
    box-shadow: 0 0 10px var(--accent-primary),
        0 0 20px var(--accent-primary);
}

@keyframes neon-flow {
    0% {
        background-position: 0% center;
    }

    100% {
        background-position: -200% center;
    }
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-lg);
    position: relative;
    z-index: 10;
}

/* Desktop Split Layout: Navigation Left, Social Right */
@media (min-width: 900px) {
    .footer-content {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
        flex-wrap: wrap;
        padding: 0 var(--space-md);
    }

    .footer-nav {
        order: 1;
        gap: var(--space-2xl);
    }

    .footer-social {
        order: 2;
    }

    /* Centered Copyright Text */
    .footer-text,
    .footer-copyright {
        order: 3;
        width: 100%;
        text-align: center;
    }

    .footer-text {
        margin-top: var(--space-xl);
        /* Balanced margin */
        margin-bottom: var(--space-xs);
    }
}

.footer-nav {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    flex-wrap: wrap;
}

.footer-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition-base);
    position: relative;
    font-size: 0.95rem;
}

.footer-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-gradient);
    transition: var(--transition-base);
}

.footer-link:hover {
    color: var(--text-primary);
}

.footer-link:hover::after {
    width: 100%;
}

.footer-social {
    display: flex;
    gap: var(--space-lg);
}

.footer-social a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-primary);
    border-radius: 50%;
    color: var(--text-secondary);
    font-size: 1.25rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.footer-social a:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
    transform: translateY(-5px) rotate(360deg);
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.3);
}

.footer-text {
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    color: var(--text-tertiary);
}

.footer-copyright {
    font-size: 0.85rem;
    color: var(--text-tertiary);
    opacity: 0.7;
    margin-top: -1rem;
}