:root {
    --bg-primary: #faf9f6;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f4f3fa;
    --text-primary: #1e1e2a;
    --text-secondary: #2d2d3a;
    --text-tertiary: #5a5a77;
    --accent-primary: #1e1e2a;
    --accent-secondary: #3a3a52;
    --border-color: #eaeaea;
    --card-bg: #ffffff;
    --header-bg: rgba(255, 255, 255, 0.9);
    --footer-bg: #1e1e2a;
    --footer-text: #dddddd;
    --code-bg: #1e1e2a;
    --code-text: #d4d4d4;
    --shadow-color: rgba(0,0,0,0.1);
    --font-primary: 'Cormorant Garamond', serif;
    --font-secondary: 'Inconsolata', monospace;
    --font-code: 'JetBrains Mono', monospace;
    --transition-speed: 0.3s;
}

[data-theme="dark"] {
    --bg-primary: #1a1a24;
    --bg-secondary: #252532;
    --bg-tertiary: #2a2a3a;
    --text-primary: #eaeaf0;
    --text-secondary: #bdbdd6;
    --text-tertiary: #b0b0c0;
    --accent-primary: #eaeaf0;
    --accent-secondary: #bdbdd6;
    --border-color: #333344;
    --card-bg: #252532;
    --header-bg: rgba(30, 30, 42, 0.9);
    --footer-bg: #0f0f15;
    --footer-text: #dddddd;
    --code-bg: #0f0f15;
    --code-text: #d4d4d4;
    --shadow-color: rgba(0,0,0,0.3);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 2rem;
    background-color: var(--header-bg);
    backdrop-filter: blur(4px);
    border-bottom: 1px solid var(--border-color);
    font-weight: 500;
    font-size: 1.1rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-left i {
    margin-right: 8px;
    color: var(--text-secondary);
}

.header-right i {
    font-size: 1.3rem;
    cursor: pointer;
    color: var(--text-secondary);
    transition: transform 0.2s;
}

.header-right i:hover {
    transform: rotate(15deg);
}

main {
    flex: 1;
    width: 100%;
    min-height: 100vh;
    margin: 0 auto;
    padding: 0.5rem 0.5rem;
}

footer {
    background-color: var(--footer-bg);
    color: var(--footer-text);
    padding: 2.5rem 2rem 1.5rem;
    font-size: 0.95rem;
    border-top: 4px solid var(--border-color);
}

.footer-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.footer-col p {
    margin: 0.5rem 0 0;
    opacity: 0.8;
}

.footer-col ul {
    list-style: none;
    margin-top: 0.5rem;
}

.footer-col li {
    margin-bottom: 0.4rem;
}

.footer-col a {
    color: #ccc;
    text-decoration: none;
    cursor: pointer;
    transition: color 0.2s;
}

.footer-col a:hover {
    color: white;
    text-decoration: underline;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 0.75rem;
}

.social-links a {
    color: #fff;
    background-color: #2f2f41;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.social-links a:hover {
    background-color: #4b4b6a;
    transform: translateY(-2px);
}

.footer-bottom {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid #333344;
    font-size: 0.85rem;
    color: #aaa;
}

.loading-spinner {
    text-align: center;
    font-size: 1.3rem;
    margin-top: 4rem;
    color: var(--text-tertiary);
}

.hidden {
    display: none !important;
}

.back-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--accent-primary);
    color: white;
    border: none;
    padding: 0.7rem 1.5rem;
    border-radius: 30px;
    font-size: 0.95rem;
    cursor: pointer;
    margin-bottom: 2rem;
    transition: 0.2s;
}

.back-button:hover {
    background: var(--accent-secondary);
    transform: translateX(-3px);
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.category-card {
    background: var(--card-bg);
    border-radius: 1.2rem;
    padding: 1.8rem;
    cursor: pointer;
    transition: all 0.25s;
    border: 1px solid var(--border-color);
    box-shadow: 0 5px 15px var(--shadow-color);
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px var(--shadow-color);
}

.category-icon {
    font-size: 2.2rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.category-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-family: var(--font-primary);
}

.category-desc {
    color: var(--text-tertiary);
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.category-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag {
    background: var(--bg-tertiary);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-family: var(--font-secondary);
}

.items-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.item-card {
    background: var(--card-bg);
    border-radius: 1.2rem;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    transition: 0.2s;
    cursor: pointer;
}

.item-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px var(--shadow-color);
}

.item-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.item-icon {
    font-size: 1.8rem;
    color: var(--text-secondary);
}

.item-title {
    font-size: 1.3rem;
    font-weight: 600;
    font-family: var(--font-primary);
}

.item-desc {
    color: var(--text-tertiary);
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.item-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.item-actions {
    display: flex;
    gap: 0.8rem;
    margin-top: 1rem;
}

.action-btn {
    background: var(--bg-tertiary);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 25px;
    font-size: 0.9rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: 0.2s;
    color: var(--text-primary);
}

.action-btn:hover {
    background: var(--accent-primary);
    color: white;
}

.code-viewer {
    background: var(--code-bg);
    border-radius: 1rem;
    padding: 1.5rem;
    margin-top: 1rem;
    font-family: var(--font-code);
    font-size: 0.9rem;
    color: var(--code-text);
    overflow-x: auto;
}

.course-content {
    margin-top: 1.5rem;
}

.content-item {
    background: var(--bg-tertiary);
    border-radius: 0.8rem;
    padding: 1.5rem;
    margin-bottom: 1rem;
}

.video-container {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    border-radius: 0.8rem;
    margin-top: 1rem;
}

.video-container iframe,
.video-container video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    margin-bottom: 1.5rem;
    color: var(--text-tertiary);
    font-size: 0.95rem;
    font-family: var(--font-secondary);
}

.breadcrumb i {
    font-size: 0.8rem;
}

.breadcrumb span {
    cursor: pointer;
    transition: color 0.2s;
}

.breadcrumb span:hover {
    color: var(--text-primary);
}

.profile-section {
    display: flex;
    align-items: center;
    min-height: 100vh;
    margin-bottom: 4rem;
}

.profile-grid {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 2.5rem;
    width: 100%;
    align-items: center;
}

.profile-left {
    text-align: center;
    align-items: center;
}

.profile-img {
    width: 100%;
    max-width: 400px;
    border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
    animation: morph 8s ease-in-out infinite;
    object-fit: cover;
    border: 2px solid var(--bg-primary);
    box-shadow: 0 20px 30px -10px var(--shadow-color);
    margin-bottom: 1.2rem;
}

.profile-name {
    font-family: var(--font-primary);
    font-size: 2.2rem;
    font-weight: 600;
    letter-spacing: 1px;
}

.profile-right {
    padding-left: 1rem;
    align-items: center;
}

.profile-desc {
    font-size: 1.4rem;
    line-height: 1.6;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-family: var(--font-primary);
}

@keyframes morph {
    0%, 100% { border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%; }
    50% { border-radius: 70% 30% 30% 70% / 60% 40% 60% 40%; }
}

.btn-scroll {
    background: var(--accent-primary);
    color: var(--text-tertiary);
    border: none;
    padding: 0.9rem 2rem;
    border-radius: 40px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: 0.2s;
}

.btn-scroll:hover {
    background: var(--accent-secondary);
    transform: scale(1.03);
}

.about-section {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem 1.8rem;
    min-height: 40vh;
    padding: 0.5rem 0.5rem;
    margin-bottom: 3rem;
}

.section-title {
    grid-column: 1 / -1;
    font-size: 2.2rem;
    font-weight: 500;
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-family: var(--font-primary);
}

.about-item {
    display: flex;
    gap: 1.2rem;
    align-items: flex-start;
}

.about-icon {
    background: var(--bg-tertiary);
    width: 52px;
    height: 52px;
    border-radius: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--text-secondary);
    flex-shrink: 0;
}

.about-text h3 {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 0.3rem;
    font-family: var(--font-primary);
}

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

.skills-section {
    padding: 0.5rem 0.5rem;
    margin-bottom: 3rem;
}

.skills-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    margin-top: 1.2rem;
}

.skill-badge {
    background: var(--bg-secondary);
    padding: 0.6rem 1.4rem;
    border-radius: 40px;
    font-size: 1rem;
    font-weight: 500;
    box-shadow: 0 2px 6px var(--shadow-color);
    border: 1px solid var(--border-color);
    transition: 0.15s;
    font-family: var(--font-secondary);
}

.skill-badge:hover {
    background: var(--accent-primary);
    color: white;
    border-color: var(--accent-primary);
}

.stats-section {
    color: var(--text-secondary);
    padding: 2.5rem 2rem;
    margin-bottom: 3rem;
}

.stats-section .section-title {
    color: var(--text-tertiary);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    text-align: center;
}

.stat-value {
    font-size: 3.2rem;
    font-weight: 700;
    line-height: 1.1;
    color: var(--text-tertiary);
    font-family: var(--font-code);
}

.stat-label {
    font-size: 0.95rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    opacity: 0.7;
    font-family: var(--font-secondary);
}

.closing-section {
    background: var(--bg-tertiary);
    border-radius: 3rem 1rem 3rem 1rem;
    padding: 3rem 2rem;
    text-align: center;
    margin-bottom: 2rem;
}

.closing-message {
    max-width: 650px;
    margin: 0 auto;
    font-size: 1.6rem;
    font-style: italic;
    font-family: var(--font-primary);
    color: var(--text-primary);
}

.closing-message i {
    font-size: 2.2rem;
    opacity: 0.3;
    margin-bottom: 1rem;
}

@media (max-width: 750px) {
    .profile-grid { grid-template-columns: 1fr; }
    .about-section { grid-template-columns: 1fr; }
    .stats-grid { grid-template-columns: 1fr 1fr; }
}