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

:root {
    --cardinal: #8C1515;
    --cardinal-dark: #6B0F0F;
    --cardinal-light: #B83A3A;
    --sandstone: #D2C295;
    --sandstone-light: #F0EBD8;
    --cool-gray: #4D4F53;
    --warm-gray: #3F3C30;
    --white: #FFFFFF;
    --off-white: #F7F5F0;
    --text-primary: #2E2D29;
    --text-secondary: #585754;
    --border: #E0DDD5;
    --shadow: rgba(0, 0, 0, 0.08);
    --shadow-strong: rgba(0, 0, 0, 0.15);
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Source Sans Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--text-primary);
    background: var(--white);
    line-height: 1.6;
}

/* ===== Typography ===== */
h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.3;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--cardinal);
    border-bottom: 3px solid var(--cardinal);
    padding-bottom: 0.5rem;
    display: inline-block;
}

h3 {
    font-size: 1.35rem;
    margin-bottom: 0.75rem;
    color: var(--warm-gray);
}

h4 {
    font-size: 1.05rem;
    margin-bottom: 0.4rem;
    color: var(--cardinal-dark);
}

p {
    margin-bottom: 1rem;
}

a {
    color: var(--cardinal);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--cardinal-light);
}

code {
    background: var(--sandstone-light);
    padding: 0.15em 0.4em;
    border-radius: 3px;
    font-size: 0.9em;
    font-family: 'Source Code Pro', 'Consolas', monospace;
}

/* ===== Layout ===== */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 5rem 0;
}

.section:nth-child(odd) {
    background: var(--white);
}

.section:nth-child(even) {
    background: var(--off-white);
}

/* ===== Navigation ===== */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--cardinal);
    box-shadow: 0 2px 8px var(--shadow-strong);
    transition: background 0.3s;
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.nav-logo {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--white);
    letter-spacing: 0.5px;
}

.nav-logo:hover {
    color: var(--sandstone-light);
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: rgba(255, 255, 255, 0.85);
    font-weight: 600;
    font-size: 0.95rem;
    padding: 0.25rem 0;
    border-bottom: 2px solid transparent;
    transition: color 0.2s, border-color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--white);
    border-bottom-color: var(--sandstone);
}

/* ===== Hero Section ===== */
.hero-section {
    padding-top: 8rem;
    text-align: center;
}

.hero-section h1 {
    color: var(--cardinal);
}

.subtitle {
    font-size: 1.15rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.hero-media {
    margin: 2rem auto;
    max-width: 800px;
}

.hero-image {
    width: 100%;
    max-height: 400px;
    object-fit: cover;
    border-radius: 8px;
    border: 1px solid var(--border);
}

.placeholder-note {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-style: italic;
    margin-top: 0.5rem;
}

.intro-text {
    max-width: 800px;
    margin: 2rem auto;
    font-size: 1.1rem;
    text-align: left;
}

/* ===== Task Cards ===== */
.task-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin: 2.5rem 0;
}

.card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 2rem 1.5rem;
    text-align: left;
    box-shadow: 0 2px 8px var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px var(--shadow-strong);
}

.card-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--cardinal);
    color: var(--white);
    border-radius: 50%;
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.card h3 {
    color: var(--cardinal-dark);
}

.card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

/* ===== GitHub Link ===== */
.github-link {
    display: inline-block;
    background: var(--warm-gray);
    color: var(--white);
    padding: 0.75rem 2rem;
    border-radius: 6px;
    font-weight: 600;
    margin-top: 1rem;
    transition: background 0.2s;
}

.github-link:hover {
    background: var(--cool-gray);
    color: var(--white);
}

/* ===== Methods Section ===== */
.methods-intro {
    margin-bottom: 2rem;
}

.architecture-diagram {
    margin: 2rem 0;
    text-align: center;
}

.diagram-image {
    max-width: 100%;
    border-radius: 8px;
    border: 1px solid var(--border);
}

.methods-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin: 2.5rem 0;
}

.method-block {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 8px var(--shadow);
}

.method-block h3 {
    color: var(--cardinal);
    border-bottom: 2px solid var(--sandstone);
    padding-bottom: 0.4rem;
    margin-bottom: 1rem;
    display: inline-block;
    font-size: 1.2rem;
}

.method-content h4 {
    margin-top: 0.8rem;
}

.method-content p {
    font-size: 0.93rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

/* ===== Node Details ===== */
.node-details {
    margin: 2.5rem 0;
}

.node-details > h3 {
    color: var(--cardinal);
    border-bottom: 3px solid var(--cardinal);
    padding-bottom: 0.5rem;
    display: inline-block;
    margin-bottom: 2rem;
}

.node-block {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: 0 2px 8px var(--shadow);
}

.node-block h4 {
    font-size: 1.15rem;
    color: var(--cardinal);
    margin-bottom: 1rem;
}

.node-image {
    width: 100%;
    border-radius: 6px;
    border: 1px solid var(--border);
}

/* ===== Software Stack ===== */
.software-stack {
    margin: 2.5rem 0;
}

.stack-items {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.stack-item {
    background: var(--white);
    border: 1px solid var(--border);
    border-left: 4px solid var(--cardinal);
    border-radius: 4px;
    padding: 1rem 1.25rem;
}

.stack-item strong {
    display: block;
    color: var(--cardinal-dark);
    margin-bottom: 0.25rem;
}

.stack-item span {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* ===== Result Media ===== */
.result-media {
    margin: 1.5rem 0;
    text-align: center;
}

.result-image {
    max-width: 100%;
    max-height: 400px;
    object-fit: contain;
    border-radius: 8px;
    border: 1px solid var(--border);
    box-shadow: 0 2px 8px var(--shadow);
}

.result-image.diagram {
    max-height: 500px;
    border: none;
    box-shadow: none;
}

.result-media-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin: 1.5rem 0;
}

.video-embed {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%;
    margin: 1.5rem 0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px var(--shadow);
}

.video-embed iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.media-caption {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
    font-style: italic;
}

/* ===== Results Section ===== */
.result-block {
    margin-bottom: 3rem;
}

.result-block:last-child {
    margin-bottom: 0;
}

.video-placeholder {
    margin: 1.5rem 0;
}

.placeholder-box {
    background: var(--sandstone-light);
    border: 2px dashed var(--sandstone);
    border-radius: 8px;
    padding: 4rem 2rem;
    text-align: center;
    color: var(--text-secondary);
    font-style: italic;
}

.key-results {
    margin-top: 1rem;
}

.key-results h4 {
    color: var(--warm-gray);
}

.key-results ul {
    list-style: none;
    padding: 0;
}

.key-results li {
    padding: 0.4rem 0 0.4rem 1.5rem;
    position: relative;
    color: var(--text-secondary);
}

.key-results li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.85rem;
    width: 8px;
    height: 8px;
    background: var(--cardinal);
    border-radius: 50%;
}

/* ===== Future Work Section ===== */
.future-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.future-card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 8px var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
}

.future-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px var(--shadow-strong);
}

.future-card h3 {
    color: var(--cardinal);
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.future-card p {
    font-size: 0.93rem;
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* ===== Team Section ===== */
.team-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    margin-bottom: 3rem;
}

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

.member-photo {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    margin: 0 auto 1rem;
    overflow: hidden;
    border: 3px solid var(--cardinal);
}

.member-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.placeholder-photo {
    background: var(--sandstone-light);
    display: flex;
    align-items: center;
    justify-content: center;
}

.placeholder-photo::after {
    content: '';
    width: 50px;
    height: 50px;
    background: var(--sandstone);
    border-radius: 50%;
}

.team-member h3 {
    font-size: 1.05rem;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.team-member .role {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0;
}

.course-info {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

.course-info p {
    margin-bottom: 0.4rem;
    color: var(--text-secondary);
}

/* ===== Footer ===== */
footer {
    background: var(--warm-gray);
    color: rgba(255, 255, 255, 0.7);
    text-align: center;
    padding: 1.5rem 0;
    font-size: 0.9rem;
}

footer p {
    margin: 0;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.6rem;
    }

    .task-cards,
    .methods-grid,
    .stack-items,
    .future-grid {
        grid-template-columns: 1fr;
    }

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

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

    .nav-links {
        gap: 1rem;
        font-size: 0.85rem;
    }
}

@media (max-width: 600px) {
    .container {
        padding: 0 1rem;
    }

    .section {
        padding: 3rem 0;
    }

    .hero-section {
        padding-top: 5rem;
    }

    h1 {
        font-size: 1.6rem;
    }

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

    .nav-links {
        gap: 0.75rem;
    }

    .nav-links a {
        font-size: 0.8rem;
    }
}