/* Reset và Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    line-height: 1.6;
    color: #333;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: all 0.3s ease;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo a {
    font-size: 1.5rem;
    font-weight: 700;
    color: #4f46e5;
    text-decoration: none;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: #333;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #4f46e5;
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background-color: #4f46e5;
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding-top: 70px;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-text h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.highlight {
    color: #fbbf24;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #e5e7eb;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    color: #d1d5db;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 12px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: #fbbf24;
    color: #1f2937;
}

.btn-primary:hover {
    background: #f59e0b;
    transform: translateY(-2px);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: #4f46e5;
}

.hero-image {
    text-align: center;
}

.profile-img {
    width: 350px;
    height: 350px;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

/* Section Styles */
section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: #1f2937;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    width: 80px;
    height: 4px;
    background: #4f46e5;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
}

/* About Section */
.about {
    background: #f9fafb;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text h3 {
    font-size: 2.2rem;
    margin-bottom: 1.2rem;
    color: #1f2937;
}

.about-text p {
    margin-bottom: 1.8rem;
    color: #6b7280;
    line-height: 2;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 2rem;
}

.stat {
    text-align: center;
}

.stat h4 {
    font-size: 2rem;
    font-weight: 700;
    color: #4f46e5;
    margin-bottom: 0.5rem;
}

.stat p {
    color: #6b7280;
    font-weight: 500;
}

.about-img {
    width: 100%;
    border-radius: 10px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

/* Skills Section */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.skill-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.skill-card:hover {
    transform: translateY(-10px);
}

.skill-icon {
    font-size: 3rem;
    color: #4f46e5;
    margin-bottom: 1rem;
}

.skill-card h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.skill-card p {
    color: #6b7280;
}

/* Experience Section */
.experience {
    background: #f9fafb;
}

.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #4f46e5;
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
    width: 50%;
}

.timeline-item:nth-child(odd) {
    left: 0;
    padding-right: 2rem;
}

.timeline-item:nth-child(even) {
    left: 50%;
    padding-left: 2rem;
}

.timeline-dot {
    position: absolute;
    width: 20px;
    height: 20px;
    background: #4f46e5;
    border-radius: 50%;
    top: 0;
}

.timeline-item:nth-child(odd) .timeline-dot {
    right: -10px;
}

.timeline-item:nth-child(even) .timeline-dot {
    left: -10px;
}

.timeline-content {
    background: white;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.timeline-content h3 {
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.timeline-date {
    color: #4f46e5;
    font-weight: 600;
    font-size: 0.9rem;
}

.timeline-content p {
    color: #6b7280;
    margin-top: 1rem;
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.project-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.project-card:hover {
    transform: translateY(-10px);
}

.project-image img {
    width: 100%;
    height: 250px;
    object-fit: cover;
}

.project-content {
    padding: 1.5rem;
}

.project-content h3 {
    color: #1f2937;
    margin-bottom: 1rem;
}

.project-content p {
    color: #6b7280;
    margin-bottom: 1rem;
}

.project-tech {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.project-tech span {
    background: #e5e7eb;
    color: #374151;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

/* Contact Section */
.contact {
    background: #f9fafb;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.contact-info > p {
    color: #6b7280;
    margin-bottom: 2rem;
}

.contact-item {
    display: flex;
    align-items: center;
    margin-bottom: 1.5rem;
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: #4f46e5;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 1rem;
    font-size: 1.2rem;
}

.contact-details h4 {
    color: #1f2937;
    margin-bottom: 0.3rem;
}

.contact-details a {
    color: #4f46e5;
    text-decoration: none;
}

.contact-details a:hover {
    text-decoration: underline;
}

.contact-form {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #e5e7eb;
    border-radius: 5px;
    font-family: inherit;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #4f46e5;
}

/* Footer */
.footer {
    background: #1f2937;
    color: white;
    padding: 2rem 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.social-links a {
    width: 40px;
    height: 40px;
    background: #4f46e5;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: background 0.3s ease;
}

.social-links a:hover {
    background: #3730a3;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

    .hero-text h1 {
        font-size: 2.5rem;
    }

    .profile-img {
        width: 250px;
        height: 250px;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .about-stats {
        grid-template-columns: repeat(3, 1fr);
        gap: 1rem;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        width: 100%;
        left: 0 !important;
        padding-left: 3rem !important;
        padding-right: 0 !important;
    }

    .timeline-dot {
        left: 10px !important;
        right: auto !important;
    }

    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .footer-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 200px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero-text h1 {
        font-size: 2rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .profile-img {
        width: 200px;
        height: 200px;
    }

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

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

/* Animation cho scroll */
.nav-link.active {
    color: #4f46e5;
}

.nav-link.active::after {
    width: 100%;
}

/* Smooth animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-text,
.hero-image {
    animation: fadeInUp 1s ease-out;
}

.hero-image {
    animation-delay: 0.3s;
}

/* Gift Section Styles */
.gift {
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e9f2 100%);
    position: relative;
    overflow: hidden;
}

.gift::before {
    content: '';
    position: absolute;
    top: -50px;
    right: -50px;
    width: 200px;
    height: 200px;
    background: rgba(79, 70, 229, 0.1);
    border-radius: 50%;
    z-index: 0;
}

.gift::after {
    content: '';
    position: absolute;
    bottom: -50px;
    left: -50px;
    width: 250px;
    height: 250px;
    background: rgba(251, 191, 36, 0.1);
    border-radius: 50%;
    z-index: 0;
}

.gift .container {
    position: relative;
    z-index: 1;
}

.gift .section-title {
    margin-bottom: 2.5rem;
}

.gift .section-title::after {
    background: #fbbf24;
}

#giftForm {
    max-width: 550px;
    margin: 0 auto;
    background: white;
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
    position: relative;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

#giftForm:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

#giftForm::before {
    content: '🎁';
    position: absolute;
    top: -25px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 3rem;
    background: white;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

#giftForm .form-group {
    margin-bottom: 1.8rem;
}

#giftForm input {
    padding: 15px;
    border: 2px solid #e5e7eb;
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

#giftForm input:focus {
    border-color: #fbbf24;
    box-shadow: 0 0 0 3px rgba(251, 191, 36, 0.2);
}

#giftForm .btn-primary {
    width: 100%;
    padding: 15px;
    font-size: 1.1rem;
    background: linear-gradient(to right, #fbbf24, #f59e0b);
    border-radius: 10px;
    transition: all 0.3s ease;
}

#giftForm .btn-primary:hover {
    background: linear-gradient(to right, #f59e0b, #d97706);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(245, 158, 11, 0.3);
}

.gift-info {
    max-width: 550px;
    margin: 2rem auto 0;
    background: linear-gradient(to right, #4f46e5, #6366f1);
    color: white;
    padding: 1.5rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 10px 30px rgba(79, 70, 229, 0.3);
    transform: scale(0.95);
    opacity: 0;
    animation: showGiftInfo 0.5s forwards;
}

@keyframes showGiftInfo {
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.gift-info p {
    font-size: 1.1rem;
    line-height: 1.6;
}

.gift-info strong {
    display: block;
    font-size: 1.3rem;
    margin-top: 0.5rem;
    color: #fbbf24;
}

@media (max-width: 768px) {
    #giftForm {
        padding: 2rem 1.5rem;
    }
}

/* Form focus effect */
.form-group.focused input {
    border-color: #4f46e5;
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.2);
}

/* Error styles */
.form-group.error input {
    border-color: #ef4444;
    background-color: rgba(239, 68, 68, 0.05);
}

.error-message {
    color: #ef4444;
    font-size: 0.85rem;
    margin-top: 0.5rem;
    animation: fadeIn 0.3s ease;
}

/* Loading spinner */
.loading-spinner {
    display: inline-block;
    width: 1.2rem;
    height: 1.2rem;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 0.8s linear infinite;
    margin-right: 0.5rem;
    vertical-align: middle;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Form success effect */
#giftForm.success {
    animation: successPulse 1s;
}

@keyframes successPulse {
    0% {
        box-shadow: 0 0 0 0 rgba(79, 70, 229, 0.7);
    }
    70% {
        box-shadow: 0 0 0 15px rgba(79, 70, 229, 0);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(79, 70, 229, 0);
    }
}

/* Notification */
.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 15px 25px;
    border-radius: 8px;
    color: white;
    font-weight: 500;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    transform: translateX(120%);
    transition: transform 0.3s ease;
    z-index: 1000;
}

.notification.show {
    transform: translateX(0);
}

.notification.success {
    background: linear-gradient(to right, #10b981, #059669);
}

.notification.error {
    background: linear-gradient(to right, #ef4444, #dc2626);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}