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

:root {
    --black: #000;
    --white: #fff;
    --gray-50: #fafafa;
    --gray-100: #f5f5f5;
    --gray-200: #e5e5e5;
    --gray-300: #d4d4d4;
    --gray-400: #a3a3a3;
    --gray-500: #737373;
    --gray-600: #525252;
    --gray-700: #404040;
    --gray-800: #262626;
    --gray-900: #171717;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--white);
    color: var(--black);
    line-height: 1.7;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 50px;
    background: var(--white);
    border-bottom: 1px solid var(--gray-100);
}

.nav-brand {
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--gray-500);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--black);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 120px 24px 80px;
    background: var(--white);
}

.hero-content {
    max-width: 600px;
}

.avatar-container {
    margin-bottom: 32px;
}

.avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    overflow: hidden;
    border: 1px solid var(--gray-200);
    margin: 0 auto;
}

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

.hero h1 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 16px;
    letter-spacing: -0.03em;
    color: var(--black);
}

.tagline {
    font-size: 1.1rem;
    color: var(--gray-500);
    margin-bottom: 40px;
    font-weight: 400;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
}

.btn {
    padding: 12px 28px;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s;
    border: 1px solid var(--gray-300);
}

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

.btn-primary:hover {
    background: var(--gray-800);
}

.btn-secondary {
    background: var(--white);
    color: var(--black);
}

.btn-secondary:hover {
    background: var(--gray-50);
}

.btn-block {
    width: 100%;
    text-align: center;
}

/* Section Styles */
section {
    padding: 80px 0;
    border-top: 1px solid var(--gray-200);
}

.section-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 48px;
    letter-spacing: -0.02em;
    text-align: left;
}

/* About Section */
.about {
    background: var(--white);
}

.about-content {
    display: block;
}

.about-text {
    background: none;
    padding: 0;
    border-radius: 0;
    border: none;
    margin-bottom: 48px;
}

.about-text .intro {
    font-size: 1.1rem;
    color: var(--black);
    margin-bottom: 24px;
    font-weight: 500;
}

.about-text p {
    color: var(--gray-600);
    margin-bottom: 16px;
    line-height: 1.8;
}

.skills {
    margin-top: 32px;
}

.skills h3 {
    font-size: 1rem;
    margin-bottom: 16px;
    color: var(--black);
    font-weight: 500;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.skill-tag {
    padding: 6px 14px;
    background: var(--gray-100);
    border: none;
    border-radius: 4px;
    font-size: 0.85rem;
    color: var(--gray-700);
}

.skill-tag:hover {
    background: var(--gray-200);
    color: var(--black);
}

.about-stats {
    display: flex;
    gap: 48px;
    padding-top: 32px;
    border-top: 1px solid var(--gray-200);
}

.stat-card {
    background: none;
    padding: 0;
    border-radius: 0;
    text-align: left;
    border: none;
}

.stat-card:hover {
    transform: none;
    box-shadow: none;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 600;
    color: var(--black);
    letter-spacing: -0.02em;
}

.stat-label {
    color: var(--gray-500);
    font-size: 0.85rem;
    margin-top: 4px;
}

/* Mood Section */
.mood {
    background: var(--gray-50);
}

.mood-composer {
    background: var(--white);
    padding: 32px;
    border-radius: 8px;
    border: 1px solid var(--gray-200);
    margin-bottom: 48px;
}

.mood-composer h3 {
    margin-bottom: 24px;
    font-size: 1rem;
    font-weight: 500;
}

.mood-selector {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.mood-label {
    color: var(--gray-600);
    font-size: 0.9rem;
}

.mood-emojis {
    display: flex;
    gap: 8px;
}

.mood-emoji-btn {
    padding: 8px 12px;
    font-size: 1.5rem;
    background: var(--white);
    border: 1px solid var(--gray-300);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
    line-height: 1;
}

.mood-emoji-btn:hover {
    border-color: var(--gray-400);
    transform: scale(1.1);
}

.mood-emoji-btn.selected {
    border-color: var(--black);
    background: var(--gray-100);
    transform: scale(1.1);
}

#mood-text {
    width: 100%;
    padding: 16px;
    background: var(--white);
    border: 1px solid var(--gray-300);
    border-radius: 6px;
    color: var(--black);
    font-size: 0.95rem;
    font-family: inherit;
    resize: vertical;
    transition: border-color 0.2s;
}

#mood-text:focus {
    outline: none;
    border-color: var(--black);
}

#mood-text::placeholder {
    color: var(--gray-400);
}

.composer-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 16px;
}

.char-count {
    color: var(--gray-400);
    font-size: 0.85rem;
}

/* Mood Timeline */
.mood-timeline h3 {
    margin-bottom: 24px;
    font-size: 1rem;
    font-weight: 500;
}

.mood-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.mood-item {
    background: var(--white);
    padding: 24px;
    border-radius: 8px;
    border: 1px solid var(--gray-200);
    position: relative;
}

.mood-item:hover {
    border-color: var(--gray-300);
}

.mood-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.mood-item-emoji {
    font-size: 1.5rem;
    line-height: 1;
}

.mood-item-time {
    color: var(--gray-400);
    font-size: 0.8rem;
}

.mood-item-content {
    color: var(--gray-700);
    line-height: 1.7;
}

.mood-item-actions {
    position: absolute;
    top: 20px;
    right: 20px;
    opacity: 0;
    transition: opacity 0.2s;
}

.mood-item:hover .mood-item-actions {
    opacity: 1;
}

.delete-btn {
    background: none;
    border: none;
    color: var(--gray-400);
    cursor: pointer;
    font-size: 1rem;
    padding: 4px;
}

.delete-btn:hover {
    color: var(--black);
}

.empty-state {
    text-align: center;
    padding: 48px 20px;
    color: var(--gray-400);
}

.empty-emoji {
    font-size: 2rem;
    display: block;
    margin-bottom: 16px;
    color: var(--gray-300);
}

/* Contact Section */
.contact {
    background: var(--white);
}

.contact-intro {
    color: var(--gray-500);
    margin-bottom: 40px;
    font-size: 1rem;
}

.contact-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 48px;
}

.contact-card {
    background: var(--gray-50);
    padding: 24px 16px;
    border-radius: 8px;
    text-align: center;
    text-decoration: none;
    color: inherit;
    border: 1px solid transparent;
    transition: all 0.2s;
    position: relative;
}

.contact-card:hover {
    border-color: var(--gray-300);
    background: var(--white);
}

.contact-icon {
    width: 28px;
    height: 28px;
    margin-bottom: 12px;
    color: var(--gray-400);
}

.contact-card:hover .contact-icon {
    color: var(--black);
}

.contact-card.copyable {
    cursor: pointer;
}

.copy-hint {
    display: block;
    font-size: 0.65rem;
    color: var(--gray-400);
    margin-top: 4px;
}

.contact-card.copied .copy-hint {
    color: var(--black);
}

.contact-card.copied::after {
    content: '已复制!';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--black);
    color: var(--white);
    padding: 6px 12px;
    border-radius: 4px;
    font-size: 0.8rem;
    animation: fadeOut 1.5s forwards;
}

@keyframes fadeOut {
    0%, 70% { opacity: 1; }
    100% { opacity: 0; }
}

.contact-card h4 {
    margin-bottom: 4px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--black);
}

.contact-card p {
    color: var(--gray-500);
    font-size: 0.8rem;
}

.contact-form-container {
    max-width: 100%;
    margin: 0;
    background: var(--gray-50);
    padding: 32px;
    border-radius: 8px;
    border: none;
}

.contact-form-container h3 {
    text-align: left;
    margin-bottom: 24px;
    font-size: 1rem;
    font-weight: 500;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--gray-600);
    font-size: 0.85rem;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 14px;
    background: var(--white);
    border: 1px solid var(--gray-300);
    border-radius: 6px;
    color: var(--black);
    font-size: 0.95rem;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--black);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--gray-400);
}

/* Footer */
.footer {
    background: var(--gray-50);
    padding: 32px 0;
    text-align: center;
    border-top: 1px solid var(--gray-200);
}

.footer p {
    color: var(--gray-500);
    font-size: 0.85rem;
    margin-bottom: 8px;
}

.footer-quote {
    font-style: italic;
    color: var(--gray-400);
    font-size: 0.8rem;
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 40px;
    height: 40px;
    background: var(--white);
    border: 1px solid var(--gray-300);
    border-radius: 6px;
    color: var(--black);
    font-size: 1rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.2s;
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--gray-100);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }
    
    .navbar {
        padding: 14px 20px;
    }
    
    .nav-brand {
        font-size: 0.95rem;
    }
    
    .nav-links {
        display: none;
    }
    
    .hero {
        min-height: auto;
        padding: 100px 20px 60px;
    }
    
    .hero h1 {
        font-size: 1.75rem;
        margin-bottom: 12px;
    }
    
    .tagline {
        font-size: 0.95rem;
        margin-bottom: 28px;
    }
    
    .avatar {
        width: 80px;
        height: 80px;
    }
    
    .avatar-container {
        margin-bottom: 24px;
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
        gap: 12px;
    }
    
    .btn {
        width: 100%;
        text-align: center;
        padding: 14px 24px;
    }
    
    section {
        padding: 50px 0;
    }
    
    .section-title {
        font-size: 1.25rem;
        margin-bottom: 32px;
    }
    
    .about-text {
        margin-bottom: 32px;
    }
    
    .about-text .intro {
        font-size: 1rem;
    }
    
    .about-text p {
        font-size: 0.9rem;
    }
    
    .skills h3 {
        font-size: 0.9rem;
    }
    
    .skill-tags {
        gap: 6px;
    }
    
    .skill-tag {
        padding: 5px 10px;
        font-size: 0.8rem;
    }
    
    .about-stats {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 20px;
        justify-content: flex-start;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .stat-label {
        font-size: 0.8rem;
    }
    
    .mood-composer {
        padding: 20px;
    }
    
    .mood-composer h3 {
        font-size: 1rem;
        margin-bottom: 16px;
    }
    
    .mood-selector {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }
    
    .mood-label {
        font-size: 0.85rem;
    }
    
    .mood-emojis {
        gap: 6px;
        flex-wrap: wrap;
    }
    
    .mood-emoji-btn {
        padding: 6px 10px;
        font-size: 1.3rem;
    }
    
    #mood-text {
        padding: 14px;
        font-size: 0.9rem;
    }
    
    .mood-timeline h3 {
        font-size: 1rem;
        margin-bottom: 16px;
    }
    
    .mood-item {
        padding: 16px;
    }
    
    .mood-item-emoji {
        font-size: 1.3rem;
    }
    
    .mood-item-time {
        font-size: 0.75rem;
    }
    
    .mood-item-content {
        font-size: 0.9rem;
    }
    
    .contact-intro {
        font-size: 0.9rem;
        margin-bottom: 28px;
    }
    
    .contact-cards {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }
    
    .contact-card {
        padding: 20px 12px;
    }
    
    .contact-icon {
        font-size: 1rem;
        margin-bottom: 8px;
    }
    
    .contact-card h4 {
        font-size: 0.8rem;
    }
    
    .contact-card p {
        font-size: 0.7rem;
    }
    
    .contact-form-container {
        padding: 20px;
    }
    
    .contact-form-container h3 {
        font-size: 1rem;
        margin-bottom: 20px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }
    
    .form-group {
        margin-bottom: 16px;
    }
    
    .form-group label {
        font-size: 0.8rem;
        margin-bottom: 6px;
    }
    
    .form-group input,
    .form-group textarea {
        padding: 12px;
        font-size: 0.9rem;
    }
    
    .footer {
        padding: 24px 0;
    }
    
    .footer p {
        font-size: 0.8rem;
    }
    
    .footer-quote {
        font-size: 0.75rem;
    }
    
    .back-to-top {
        width: 36px;
        height: 36px;
        font-size: 0.9rem;
        bottom: 20px;
        right: 20px;
    }
    
    .empty-state {
        padding: 32px 16px;
    }
    
    .empty-emoji {
        font-size: 1.5rem;
        margin-bottom: 12px;
    }
    
    .empty-state p {
        font-size: 0.85rem;
    }
}

@media (max-width: 380px) {
    .container {
        padding: 0 16px;
    }
    
    .navbar {
        padding: 12px 16px;
    }
    
    .hero {
        padding: 90px 16px 50px;
    }
    
    .hero h1 {
        font-size: 1.5rem;
    }
    
    .tagline {
        font-size: 0.85rem;
    }
    
    .avatar {
        width: 70px;
        height: 70px;
    }
    
    .contact-cards {
        grid-template-columns: 1fr 1fr;
    }
    
    .about-stats {
        gap: 16px;
    }
    
    .mood-emojis {
        width: 100%;
    }
    
    .mood-emoji-btn {
        flex: 1;
        min-width: calc(25% - 6px);
        text-align: center;
    }
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--black);
    padding: 12px 24px;
    border-radius: 6px;
    color: var(--white);
    font-size: 0.9rem;
    font-weight: 500;
    opacity: 0;
    transition: all 0.2s;
    z-index: 10000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast.success,
.toast.error {
    border: none;
}