/* --- Header & Navigation --- */
.site-header {
    background: var(--color-surface);
    margin: 1rem auto 0;
    width: min(calc(100% - 2rem), var(--max-width));
    border-radius: 1rem;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--color-border);
    position: fixed;
    top: 1rem;
    left: 0;
    right: 0;
    z-index: 100;
    transition: transform 0.6s cubic-bezier(0.33, 1, 0.68, 1), opacity 0.4s ease;
    height: auto;
}

body.scrolled-mode .site-header {
    transform: translateY(-200%) !important;
    opacity: 0 !important;
    pointer-events: none !important;
}

body.scrolled-mode .site-header.is-hovered {
    transform: translateY(0) !important;
    opacity: 1 !important;
    pointer-events: auto !important;
}

.nav {
    max-width: 100%;
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: flex-start;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    color: #1a202c;
    text-decoration: none;
    padding: 0.5rem 0.75rem;
    border-radius: 1rem;
    transition: background-color 0.2s ease, transform 0.2s ease;
}

.nav-logo:hover {
    background-color: rgba(0, 0, 0, 0.05);
    border-bottom-color: transparent;
    transform: translateY(-2px);
}

[data-theme="dark"] .nav-logo:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.nav-logo img {
    height: 40px;
    width: auto;
    display: block;
}

.nav-list {
    list-style: none;
    display: flex;
    gap: var(--spacing-lg);
    padding: 0;
    margin: 0 0 0 auto;
}

.nav-list a {
    padding: 0.5rem 0.75rem;
    border-radius: 1rem;
    transition: background-color 0.2s ease, transform 0.2s ease;
    display: inline-block;
}

.nav-list a:hover {
    background-color: rgba(0, 0, 0, 0.05);
    border-bottom-color: transparent;
    transform: translateY(-2px);
}

.nav-list a[aria-current="page"] {
    background-color: rgba(0, 0, 0, 0.08);
    font-weight: 600;
}

[data-theme="dark"] .nav-list a:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .nav-list a[aria-current="page"] {
    background-color: rgba(255, 255, 255, 0.15);
}

.header-controls {
    margin-left: 2rem;
    display: flex;
    align-items: center;
}

/* --- Container & Content --- */
.site-content {
    flex: 1;
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--spacing-lg) var(--spacing-md);
    display: flex;
    flex-direction: column;
}

.site-content>*:only-child {
    flex: 1;
}

.site-footer {
    background: var(--color-surface);
    text-align: center;
    padding: var(--spacing-md) 0;
    border-top: 1px solid var(--color-border);
    color: var(--color-text-muted);
}

/* --- Collapsed UI (Sidebar, Fixed Logo) --- */
.collapsed-logo-fixed {
    position: fixed;
    top: 2rem;
    left: 2rem;
    z-index: 90;
    opacity: 0;
    transform: translateX(-20px);
    transition: opacity 0.4s, transform 0.4s;
    pointer-events: none;
    display: block;
}

.collapsed-logo-fixed img {
    height: 40px;
    width: auto;
}

.collapsed-side-nav {
    position: fixed;
    top: 8rem;
    left: 2rem;
    z-index: 90;
    opacity: 0;
    transform: translateX(-20px);
    transition: opacity 0.4s 0.1s, transform 0.4s 0.1s;
    pointer-events: none;
}

.collapsed-side-nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.collapsed-chapter-indicator {
    position: fixed;
    top: 50%;
    right: 2rem;
    transform: translateY(-50%) translateX(20px);
    z-index: 90;
    opacity: 0;
    transition: opacity 0.4s 0.2s, transform 0.4s 0.2s;
    pointer-events: none;
    text-align: right;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.header-line-trigger {
    position: fixed;
    top: 120px;
    /* Adjust via JS usually */
    left: 0;
    right: 0;
    margin: 0 auto;
    width: min(calc(100% - 4rem), var(--max-width));
    height: 3px;
    background: var(--color-primary);
    border-radius: 2px;
    z-index: 99;
    cursor: pointer;
    transition: opacity 0.3s;
    pointer-events: auto;
    padding: 10px 0;
    background-clip: content-box;
}

/* Scrolled State Logic */
body.scrolled-mode:not(.header-hover-active) .collapsed-logo-fixed,
body.scrolled-mode:not(.header-hover-active) .collapsed-side-nav,
body.scrolled-mode:not(.header-hover-active) .collapsed-chapter-indicator {
    opacity: 1 !important;
    transform: translate(0) !important;
    pointer-events: auto !important;
}

body.header-hover-active .collapsed-logo-fixed,
body.header-hover-active .collapsed-side-nav,
body.header-hover-active .collapsed-chapter-indicator {
    opacity: 0 !important;
    pointer-events: none !important;
}

/* --- Structure --- */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.hero-content {
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
    padding: 6rem 1rem 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.hero-headline {
    font-size: 5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -2px;
}

.hero-subtext {
    font-size: 1.5rem;
    color: var(--color-text-muted);
    line-height: 1.6;
    margin-bottom: 4rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* --- Page Sections --- */
.hero,
.projects-intro,
.about-intro,
.blog-intro,
.impressum,
.contact-header {
    text-align: center;
    padding-top: calc(var(--spacing-xl) + 6rem);
    padding-bottom: var(--spacing-xl);
}

.features,
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

/* About Page Layout */
.about-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 4rem;
    min-height: 100vh;
    align-items: center;
    padding-top: 8rem;
}

.about-sidebar {
    position: sticky;
    top: 8rem;
}

.about-title {
    font-size: 3.5rem;
    line-height: 1;
    margin-bottom: 0.5rem;
}

.about-subtitle {
    margin-top: 1rem;
    color: var(--color-text);
    font-size: 1.25rem;
}

.about-connect {
    margin-top: 3rem;
}

.about-main {
    border-left: 1px solid var(--color-border);
    padding-left: 2rem;
}

.about-content>div {
    margin-bottom: 4rem;
}

/* Skills Grid (About Page) */
.skills-grid {
    display: flex;
    flex-direction: column;
    gap: 0;
    margin-top: 1.5rem;
    border-top: 1px solid var(--color-border);
}

.skills-showcase {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 2rem;
    margin-top: 1rem;
}

/* Contact Page Layout */
.contact-page-wrapper {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 2rem 0;
}

.contact-header {
    background-color: var(--color-cta-bg);
    color: var(--color-cta-text);
    padding: var(--spacing-xl) var(--spacing-md);
    text-align: center;
    border-radius: 1rem;
    margin: 0 auto var(--spacing-lg);
    max-width: var(--max-width);
    width: auto;
    border-bottom: none;
}

.contact-split-block {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    background-color: var(--color-surface);
    margin: var(--spacing-xl) 0;
    padding: var(--spacing-xl);
    border-radius: 1rem;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
}

.contact-cta {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
    background-color: var(--color-cta-bg);
    color: var(--color-cta-text);
    border-radius: 1rem;
    margin: var(--spacing-lg) auto;
    max-width: var(--max-width);
    width: auto;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.cta-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-top: 2rem;
    align-items: center;
    justify-content: center;
}

/* Blog Detail Layout */
.blog-post {
    max-width: 800px;
    margin: 0 auto;
    padding: 8rem 0 2rem;
}

.blog-header {
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 1rem;
}

.blog-content p {
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.blog-footer {
    margin-top: 3rem;
}

/* --- Homepage Redesign (New Layout) --- */

/* --- Responsive Layout --- */
@media (min-width: 768px) {
    .about-grid {
        grid-template-columns: 300px 1fr;
        align-items: start;
    }
}

@media (max-width: 480px) {
    .site-content {
        padding: 2rem 1rem;
    }

    .hero-content {
        padding: 0 0.75rem;
    }

    .hero-headline {
        font-size: 2.5rem;
        margin-bottom: 1rem;
        letter-spacing: -1px;
    }

    .hero-subtext {
        font-size: 1.1rem;
        margin-bottom: 2rem;
    }

    .about-grid {
        padding-top: 5rem;
        gap: 1.5rem;
    }

    .skills-showcase {
        grid-template-columns: 1fr;
    }

    .project-grid,
    .features {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

@media (max-width: 768px) {
    .site-header {
        width: calc(100% - 1rem);
        border-radius: 0.5rem;
        top: 0.5rem;
    }

    .nav {
        padding: 0.75rem 1rem;
    }

    .nav-logo {
        padding: 0.5rem;
    }

    .nav-logo img {
        height: 32px;
    }

    .nav-toggle {
        display: block;
        font-size: 1.5rem;
        padding: 0.5rem;
        min-width: 44px;
        min-height: 44px;
    }

    .nav-list {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--color-surface);
        flex-direction: column;
        padding: 1rem;
        border-bottom: 1px solid var(--color-border);
        box-shadow: var(--shadow-md);
        gap: 0.5rem;
        border-radius: 0 0 0.5rem 0.5rem;
    }

    .nav-list a {
        padding: 0.75rem 1rem;
        min-height: 44px;
        display: flex;
        align-items: center;
        width: 100%;
    }

    .nav-list.is-open {
        display: flex;
    }

    .header-controls {
        margin-left: auto;
    }

    .icon-btn {
        min-width: 44px;
        min-height: 44px;
        font-size: 1.5rem;
    }

    .about-main {
        border-left: none;
        padding-left: 0;
    }

    .about-sidebar {
        position: static;
        text-align: center;
        margin-bottom: 2rem;
    }

    .about-title {
        font-size: 2.5rem;
    }

    .about-grid {
        display: flex;
        flex-direction: column;
        align-items: stretch;
        min-height: auto;
        padding-top: 6rem;
        gap: 2rem;
    }

    .contact-split-block {
        grid-template-columns: 1fr;
        padding: 1.5rem;
        margin: 2rem 0;
        gap: 2rem;
    }

    .contact-page-wrapper {
        padding: 1rem 0;
    }

    .collapsed-logo-fixed,
    .collapsed-side-nav,
    .collapsed-chapter-indicator,
    .header-line-trigger {
        display: none !important;
    }
}