/* ===== CSS Variables - Logo Color Scheme ===== */
:root {
    --navy: #1B2A4A;
    --navy-dark: #111D33;
    --navy-light: #2C4066;
    --gray: #7A7D82;
    --gray-light: #B0B3B8;
    --gray-bg: #F4F5F7;
    --white: #FFFFFF;
    --text-primary: #1B2A4A;
    --text-secondary: #4A5568;
    --text-light: #718096;
    --border: #E2E8F0;
    --shadow: 0 2px 12px rgba(27, 42, 74, 0.08);
    --shadow-lg: 0 8px 30px rgba(27, 42, 74, 0.12);
    --transition: 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 70px;
}

body {
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-primary);
    line-height: 1.7;
    background: var(--white);
}

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

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Navigation ===== */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}

#navbar.scrolled {
    box-shadow: var(--shadow);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

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

.nav-links {
    display: flex;
    gap: 8px;
}

.nav-links li a {
    padding: 8px 14px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: 6px;
    transition: var(--transition);
    white-space: nowrap;
}

.nav-links li a:hover,
.nav-links li a.active {
    color: var(--navy);
    background: var(--gray-bg);
}

/* Mobile Nav Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--navy);
    border-radius: 2px;
    transition: var(--transition);
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

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

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== Hero Section ===== */
#hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(135deg, var(--navy-dark) 0%, var(--navy) 50%, var(--navy-light) 100%);
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="60" height="60"><defs><pattern id="g" width="60" height="60" patternUnits="userSpaceOnUse"><path d="M0 30h60M30 0v60" stroke="rgba(255,255,255,0.04)" stroke-width="1"/></pattern></defs><rect fill="url(%23g)" width="60" height="60"/></svg>');
}

.hero-content {
    position: relative;
    z-index: 1;
    padding: 24px;
}

.hero-logo {
    width: 200px;
    margin: 0 auto 32px;
    filter: brightness(0) invert(1);
    opacity: 0.95;
}

#hero h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    color: var(--white);
    margin-bottom: 16px;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    color: var(--gray-light);
    margin-bottom: 8px;
    font-weight: 300;
}

.hero-tagline {
    font-size: clamp(0.9rem, 2vw, 1.05rem);
    color: rgba(255, 255, 255, 0.5);
    margin-bottom: 40px;
    font-weight: 300;
    font-style: italic;
}

.btn {
    display: inline-block;
    padding: 14px 32px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
}

.btn-primary {
    background: var(--white);
    color: var(--navy);
}

.btn-primary:hover {
    background: var(--gray-bg);
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

/* ===== Sections ===== */
.section {
    padding: 100px 0;
}

.section-alt {
    background: var(--gray-bg);
}

.section-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 700;
    color: var(--navy);
    text-align: center;
    margin-bottom: 12px;
    letter-spacing: -0.01em;
}

.section-divider {
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--navy), var(--gray));
    margin: 0 auto 40px;
    border-radius: 2px;
}

.section-intro {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 48px;
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ===== About Section ===== */
.about-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 48px;
    align-items: center;
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 16px;
    font-size: 1.05rem;
    line-height: 1.8;
}

.about-stats {
    display: flex;
    gap: 40px;
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    color: var(--navy);
    line-height: 1;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-light);
}

.about-logo-img {
    max-width: 280px;
    margin: 0 auto;
    opacity: 0.9;
}

/* ===== Team Profiles ===== */
.team-profiles {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.profile-card {
    display: flex;
    gap: 24px;
    background: var(--white);
    border-radius: 12px;
    padding: 28px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: var(--transition);
}

.profile-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.profile-photo {
    flex-shrink: 0;
}

.profile-placeholder {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--navy), var(--navy-light));
    color: var(--white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: 1px;
}

.profile-photo img {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    object-position: center 15%;
}

.profile-info h3 {
    font-size: 1.15rem;
    color: var(--navy);
    margin-bottom: 4px;
}

.profile-role {
    font-size: 0.85rem;
    color: var(--gray);
    font-weight: 500;
    margin-bottom: 12px;
}

.profile-skills {
    list-style: none;
    padding: 0;
}

.profile-skills li {
    padding: 3px 0 3px 16px;
    position: relative;
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.profile-skills li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    background: var(--navy);
    border-radius: 50%;
}

/* ===== Project Banner ===== */
.project-banner {
    position: relative;
    background: linear-gradient(135deg, rgba(18,30,51,0.82) 0%, rgba(27,42,74,0.78) 50%, rgba(37,58,94,0.75) 100%),
                url('images/project-rendering.png') center/cover no-repeat;
    color: var(--white);
    text-align: center;
    overflow: hidden;
}

.project-banner-overlay {
    position: absolute;
    inset: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="60" height="60"><defs><pattern id="g" width="60" height="60" patternUnits="userSpaceOnUse"><path d="M0 30h60M30 0v60" stroke="rgba(255,255,255,0.03)" stroke-width="1"/></pattern></defs><rect fill="url(%23g)" width="60" height="60"/></svg>');
}

.project-banner-content {
    position: relative;
    z-index: 1;
}

.project-label {
    display: inline-block;
    background: rgba(255, 255, 255, 0.15);
    padding: 6px 20px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: 20px;
}

.project-banner h2 {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.project-banner > .container > p {
    max-width: 700px;
    margin: 0 auto 40px;
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
}

.project-banner-content > p {
    max-width: 700px;
    margin: 0 auto 40px;
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
}

.project-quick-facts {
    display: flex;
    justify-content: center;
    gap: 48px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.quick-fact {
    text-align: center;
}

.fact-value {
    display: block;
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.fact-label {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.6);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* ===== Alternatives ===== */
.alternatives {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

.alt-card {
    background: var(--white);
    border-radius: 12px;
    padding: 28px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    position: relative;
}

.alt-card h3 {
    font-size: 1.05rem;
    color: var(--navy);
    margin-bottom: 8px;
    padding-right: 60px;
}

.alt-cost {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--navy);
    margin-bottom: 16px;
}

.alt-card ul {
    list-style: none;
    padding: 0;
    margin-bottom: 16px;
}

.alt-card ul li {
    padding: 4px 0 4px 18px;
    position: relative;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.alt-card ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 11px;
    width: 6px;
    height: 6px;
    background: var(--gray);
    border-radius: 50%;
}

.alt-score {
    font-size: 0.9rem;
    color: var(--text-light);
    padding-top: 12px;
    border-top: 1px solid var(--border);
}

.alt-selected {
    border: 2px solid var(--navy);
    box-shadow: var(--shadow-lg);
}

.alt-selected .alt-card ul li::before {
    background: var(--navy);
}

.alt-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    background: var(--navy);
    color: var(--white);
    font-size: 0.7rem;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.subsection-title {
    font-size: 1.5rem;
    color: var(--navy);
    text-align: center;
    margin-bottom: 32px;
}

/* ===== Two Column Layout ===== */
.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: start;
}

.col-text h3 {
    font-size: 1.3rem;
    color: var(--navy);
    margin: 24px 0 12px;
}

.col-text h3:first-child {
    margin-top: 0;
}

.col-text p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.col-text ul {
    list-style: none;
    padding: 0;
}

.col-text ul li {
    padding: 8px 0 8px 24px;
    position: relative;
    color: var(--text-secondary);
}

.col-text ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 16px;
    width: 8px;
    height: 8px;
    background: var(--navy);
    border-radius: 50%;
}

.col-image {
    position: sticky;
    top: 90px;
}

.col-image img {
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
}

.caption {
    text-align: center;
    font-size: 0.875rem;
    color: var(--text-light);
    margin-top: 12px;
    font-style: italic;
}

/* ===== Cards Grid ===== */
.cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.card {
    background: var(--white);
    border-radius: 12px;
    padding: 32px 24px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border);
}

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

.card-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-bg);
    border-radius: 10px;
    margin-bottom: 16px;
    color: var(--navy);
}

.card-icon svg {
    width: 24px;
    height: 24px;
}

.card h3 {
    font-size: 1.1rem;
    color: var(--navy);
    margin-bottom: 8px;
}

.card p {
    font-size: 0.925rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===== Design Criteria Tables ===== */
.criteria-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.criteria-group {
    background: var(--white);
    border-radius: 12px;
    padding: 32px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.criteria-group h3 {
    font-size: 1.2rem;
    color: var(--navy);
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--navy);
}

.criteria-group table {
    width: 100%;
    border-collapse: collapse;
}

.criteria-group table tr td {
    padding: 8px 4px;
    font-size: 0.9rem;
    border-bottom: 1px solid var(--border);
}

.criteria-group table tr td:first-child {
    color: var(--text-secondary);
    font-weight: 400;
}

.criteria-group table tr td:last-child {
    text-align: right;
    font-weight: 600;
    color: var(--navy);
}

.criteria-group table tr:last-child td {
    border-bottom: none;
}

.criteria-standards {
    margin-top: 16px;
    font-size: 0.8rem;
    color: var(--text-light);
    text-align: center;
    font-style: italic;
}

/* ===== Engineering Grid ===== */
.eng-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.eng-item {
    background: var(--white);
    border-radius: 12px;
    padding: 28px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    border-top: 3px solid var(--navy);
}

.eng-item h3 {
    font-size: 1.05rem;
    color: var(--navy);
    margin-bottom: 12px;
}

.eng-item p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== Community Impact ===== */
.impact-intro {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 48px;
}

.impact-intro p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.impact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

.impact-card {
    text-align: center;
    padding: 40px 24px;
    background: linear-gradient(135deg, var(--navy-dark), var(--navy));
    border-radius: 12px;
    color: var(--white);
}

.impact-number {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 8px;
    line-height: 1;
}

.impact-card h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--gray-light);
}

.impact-card p {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.75);
    line-height: 1.6;
}

.impact-benefits {
    background: var(--gray-bg);
    border-radius: 12px;
    padding: 40px;
}

.impact-benefits h3 {
    font-size: 1.3rem;
    color: var(--navy);
    margin-bottom: 20px;
}

.impact-benefits ul {
    list-style: none;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px 32px;
}

.impact-benefits ul li {
    padding: 8px 0 8px 28px;
    position: relative;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.impact-benefits ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 16px;
    width: 12px;
    height: 12px;
    border: 2px solid var(--navy);
    border-radius: 50%;
}

/* ===== Gallery ===== */
.gallery {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.gallery-item img {
    border-radius: 10px;
    box-shadow: var(--shadow);
    cursor: pointer;
    transition: var(--transition);
    width: 100%;
    aspect-ratio: 4/3;
    object-fit: cover;
}

.gallery-item img:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-lg);
}

.gallery-featured {
    grid-column: 1 / -1;
}

.gallery-featured img {
    aspect-ratio: 21/9;
    object-fit: cover;
    object-position: center 60%;
}

.placeholder-box {
    aspect-ratio: 4/3;
    background: var(--white);
    border: 2px dashed var(--border);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.placeholder-box p {
    color: var(--text-light);
    font-size: 0.95rem;
    font-weight: 500;
}

.placeholder-box span {
    font-size: 0.8rem;
    font-weight: 400;
    color: var(--gray-light);
}

/* ===== Video ===== */
.video-container {
    max-width: 800px;
    margin: 0 auto;
}

.video-placeholder {
    aspect-ratio: 16/9;
    background: var(--gray-bg);
    border: 2px dashed var(--border);
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 16px;
    color: var(--text-light);
}

.video-placeholder svg {
    opacity: 0.4;
}

.video-placeholder p {
    font-size: 1.1rem;
    font-weight: 500;
}

/* ===== Team ===== */
.team-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    max-width: 800px;
    margin: 0 auto;
}

.team-member {
    text-align: center;
}

.team-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--navy), var(--navy-light));
    color: var(--white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    font-weight: 700;
    margin: 0 auto 12px;
    letter-spacing: 1px;
}

.team-member h3 {
    font-size: 0.95rem;
    color: var(--navy);
    font-weight: 600;
}

/* ===== Footer ===== */
footer {
    background: var(--navy-dark);
    color: rgba(255, 255, 255, 0.7);
    text-align: center;
    padding: 48px 24px;
}

.footer-logo {
    height: 36px;
    margin: 0 auto 16px;
    filter: brightness(0) invert(1);
    opacity: 0.8;
}

footer p {
    font-size: 0.875rem;
    margin-bottom: 4px;
}

/* ===== Responsive: Tablet ===== */
@media (max-width: 1024px) {
    .cards,
    .criteria-grid,
    .eng-grid,
    .alternatives {
        grid-template-columns: repeat(2, 1fr);
    }

    .impact-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .gallery {
        grid-template-columns: repeat(2, 1fr);
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .about-logo-img {
        max-width: 200px;
    }

    .nav-links li a {
        padding: 8px 10px;
        font-size: 0.8rem;
    }
}

/* ===== Responsive: Mobile ===== */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 16px 24px;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow);
        gap: 4px;
    }

    .nav-links.open {
        display: flex;
    }

    .nav-links li a {
        display: block;
        padding: 12px 16px;
        font-size: 1rem;
    }

    .section {
        padding: 64px 0;
    }

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

    .col-image {
        position: static;
    }

    .cards,
    .criteria-grid,
    .eng-grid,
    .impact-grid,
    .alternatives {
        grid-template-columns: 1fr;
    }

    .team-profiles {
        grid-template-columns: 1fr;
    }

    .profile-card {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .profile-skills li {
        text-align: left;
    }

    .about-stats {
        justify-content: center;
    }

    .project-quick-facts {
        gap: 24px;
    }

    .gallery {
        grid-template-columns: 1fr;
    }

    .impact-benefits ul {
        grid-template-columns: 1fr;
    }

    .impact-benefits {
        padding: 24px;
    }

    .team-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }

    .hero-logo {
        width: 150px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .team-grid {
        grid-template-columns: 1fr 1fr;
        gap: 20px;
    }

    .impact-number {
        font-size: 2.2rem;
    }

    .criteria-group {
        padding: 20px;
    }
}

/* ===== Scroll Animations ===== */
.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}