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

:root {
    /* Light Theme Colors */
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #f59e0b;
    --accent-color: #10b981;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Typography */
    --font-family: 'Cairo', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    /* Spacing */
    --spacing-1: 0.25rem;
    --spacing-2: 0.5rem;
    --spacing-3: 0.75rem;
    --spacing-4: 1rem;
    --spacing-5: 1.25rem;
    --spacing-6: 1.5rem;
    --spacing-8: 2rem;
    --spacing-10: 2.5rem;
    --spacing-12: 3rem;
    --spacing-16: 4rem;
    --spacing-20: 5rem;
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.375rem;
    --radius-lg: 0.5rem;
    --radius-xl: 0.75rem;
    --radius-2xl: 1rem;
    
    /* Transitions */
    --transition-fast: 0.15s ease-in-out;
    --transition-normal: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;
}

/* Dark Theme Colors */
.dark-theme {
    --primary-color: #3b82f6;
    --primary-dark: #2563eb;
    --secondary-color: #f59e0b;
    --accent-color: #10b981;
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-light: #9ca3af;
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    --border-color: #374151;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.3), 0 8px 10px -6px rgb(0 0 0 / 0.3);
}

/* Base Styles */
html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-4);
}

@media (min-width: 640px) {
    .container {
        padding: 0 var(--spacing-6);
    }
}

@media (min-width: 1024px) {
    .container {
        padding: 0 var(--spacing-8);
    }
}

/* Sections */
.section {
    padding: var(--spacing-16) 0;
}

@media (min-width: 768px) {
    .section {
        padding: var(--spacing-20) 0;
    }
}

.section__header {
    text-align: center;
    margin-bottom: var(--spacing-12);
}

.section__title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-4);
}

@media (min-width: 768px) {
    .section__title {
        font-size: var(--font-size-4xl);
    }
}

.section__description {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.dark-theme .header {
    background-color: rgba(17, 24, 39, 0.95);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-4) 0;
}

.nav__brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.nav__logo {
    width: 40px;
    height: 40px;
    transition: transform var(--transition-normal);
}

.nav__logo:hover {
    transform: scale(1.1);
}

.nav__title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--primary-color);
}

.nav__menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-8);
}

.nav__list {
    display: flex;
    list-style: none;
    gap: var(--spacing-6);
}

.nav__link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav__link:hover,
.nav__link.active {
    color: var(--primary-color);
}

.nav__link.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
    border-radius: var(--radius-sm);
}

.nav__actions {
    display: flex;
    gap: var(--spacing-3);
    align-items: center;
}

.nav__actions .theme-toggle {
    position: static;
    width: 40px;
    height: 40px;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    color: var(--text-primary);
    font-size: var(--font-size-base);
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
}

.nav__actions .theme-toggle:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: scale(1.05);
}

.nav__toggle {
    display: none;
    background: none;
    border: none;
    font-size: var(--font-size-xl);
    color: var(--text-primary);
    cursor: pointer;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-2);
    padding: var(--spacing-3) var(--spacing-6);
    border: none;
    border-radius: var(--radius-lg);
    font-family: inherit;
    font-size: var(--font-size-base);
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

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

.btn--primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn--outline {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn--outline:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn--large {
    padding: var(--spacing-4) var(--spacing-8);
    font-size: var(--font-size-lg);
}

.btn--full {
    width: 100%;
    justify-content: center;
}

/* Hero Section */
.hero {
    padding-top: calc(80px + var(--spacing-20));
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    position: relative;
    overflow: hidden;
}

.hero__container {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-12);
    align-items: center;
}

@media (min-width: 1024px) {
    .hero__container {
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-16);
    }
}

.hero__title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-6);
    color: var(--text-primary);
}

@media (min-width: 768px) {
    .hero__title {
        font-size: var(--font-size-5xl);
    }
}

.hero__title--highlight {
    color: var(--primary-color);
    position: relative;
}

.hero__title--highlight::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-sm);
}

.hero__description {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-8);
    line-height: 1.7;
}

.hero__actions {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4);
}

@media (min-width: 640px) {
    .hero__actions {
        flex-direction: row;
        gap: var(--spacing-6);
    }
}

.hero__image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero__image-container {
    position: relative;
    max-width: 500px;
    width: 100%;
}

.hero__img {
    width: 100%;
    height: auto;
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl);
}

.hero__floating-elements {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.floating-element {
    position: absolute;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--font-size-xl);
    box-shadow: var(--shadow-lg);
    animation: float 3s ease-in-out infinite;
}

.floating-element--1 {
    top: 10%;
    right: -10%;
    animation-delay: 0s;
}

.floating-element--2 {
    bottom: 20%;
    left: -15%;
    animation-delay: 1s;
}

.floating-element--3 {
    top: 60%;
    right: -5%;
    animation-delay: 2s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-20px);
    }
}

/* Features Section */
.features {
    background-color: var(--bg-secondary);
}

.features__grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-8);
}

@media (min-width: 640px) {
    .features__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .features__grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 1280px) {
    .features__grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

.feature__card {
    background-color: var(--bg-primary);
    padding: var(--spacing-8);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: all var(--transition-normal);
    border: 1px solid var(--border-color);
}

.feature__card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.feature__icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-6);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--font-size-2xl);
}

.feature__title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-4);
}

.feature__description {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* About Section */
.about__container {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-12);
    align-items: center;
}

@media (min-width: 1024px) {
    .about__container {
        grid-template-columns: 2fr 1fr;
        gap: var(--spacing-16);
    }
}

.about__info {
    margin-bottom: var(--spacing-8);
}

.about__item {
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
    margin-bottom: var(--spacing-6);
    padding: var(--spacing-4);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
}

.about__icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--font-size-lg);
    flex-shrink: 0;
}

.about__text h4 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-1);
}

.about__text p {
    color: var(--text-secondary);
}

.about__achievements {
    margin-top: var(--spacing-8);
}

.about__achievements-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-6);
}

.achievements__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-4);
}

.achievement__item {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    padding: var(--spacing-4);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    transition: all var(--transition-fast);
}

.achievement__item:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.achievement__item i {
    color: var(--secondary-color);
    font-size: var(--font-size-lg);
}

.achievement__item:hover i {
    color: white;
}

.about__image-container {
    position: relative;
    border-radius: var(--radius-2xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.about__img {
    width: 100%;
    height: auto;
    display: block;
}

.about__image-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(transparent, rgba(0, 0, 0, 0.8));
    color: white;
    padding: var(--spacing-6);
}

.overlay__content h4 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-1);
}

.overlay__content p {
    color: rgba(255, 255, 255, 0.9);
}

/* Contact Section */
.contact {
    background-color: var(--bg-secondary);
}

.contact__container {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-12);
}

@media (min-width: 1024px) {
    .contact__container {
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-16);
    }
}

.contact__info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-6);
}

.contact__item {
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
    padding: var(--spacing-6);
    background-color: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: all var(--transition-normal);
}

.contact__item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.contact__icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--font-size-xl);
    flex-shrink: 0;
}

.contact__details h4 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-1);
}

.contact__details p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-2);
}

.contact__link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.contact__link:hover {
    color: var(--primary-dark);
}

/* Forms */
.form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-6);
}

.form__group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2);
}

.form__label {
    font-weight: 600;
    color: var(--text-primary);
}

.form__input,
.form__textarea,
.form__select {
    padding: var(--spacing-3) var(--spacing-4);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    font-family: inherit;
    font-size: var(--font-size-base);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

/* Ensure default state is always applied */
.form__input:not(.has-error):not(.is-valid) {
    border-color: var(--border-color) !important;
}

/* Default state - normal border color */
.form__input {
    border-color: var(--border-color) !important;
}

/* Invalid state - only when user has typed and it's invalid */
.form__input.has-error {
    border-color: #ef4444 !important;
}

/* Valid state - only when user has typed and it's valid */
.form__input.is-valid {
    border-color: #10b981 !important;
}

/* Dark theme adjustments */
.dark-theme .form__input.has-error {
    border-color: #fca5a5 !important;
}

.dark-theme .form__input.is-valid {
    border-color: #34d399 !important;
}

.form__input::placeholder {
    color: var(--text-light);
    opacity: 0.8;
}

.form__input:focus,
.form__textarea:focus,
.form__select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form__textarea {
    resize: vertical;
    min-height: 120px;
}

.form__options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-4);
}

.form__checkbox {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
    cursor: pointer;
    font-size: var(--font-size-sm);
}

.form__checkbox input[type="checkbox"] {
    display: none;
}

.checkmark {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.form__checkbox input[type="checkbox"]:checked + .checkmark {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.form__checkbox input[type="checkbox"]:checked + .checkmark::after {
    content: '✓';
    color: white;
    font-size: var(--font-size-xs);
    font-weight: bold;
}

.form__link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.form__link:hover {
    color: var(--primary-dark);
}

/* Footer */
.footer {
    background-color: var(--bg-tertiary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-16) 0 var(--spacing-8);
}

.footer__content {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-8);
    margin-bottom: var(--spacing-8);
}

@media (min-width: 768px) {
    .footer__content {
        grid-template-columns: 1fr 2fr;
        gap: var(--spacing-12);
    }
}

.footer__brand {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4);
}

.footer__logo {
    width: 50px;
    height: 50px;
    transition: transform var(--transition-normal);
}

.footer__logo:hover {
    transform: scale(1.1) rotate(5deg);
}

.footer__title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--primary-color);
}

.footer__description {
    color: var(--text-secondary);
    line-height: 1.6;
}

.footer__links {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-8);
}

@media (min-width: 640px) {
    .footer__links {
        grid-template-columns: repeat(2, 1fr);
    }
}

.footer__section-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-4);
}

.footer__list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2);
}

.footer__link {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.footer__link:hover {
    color: var(--primary-color);
}

.footer__bottom {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4);
    padding-top: var(--spacing-8);
    border-top: 1px solid var(--border-color);
    align-items: center;
}

@media (min-width: 768px) {
    .footer__bottom {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
    }
}

.footer__copyright {
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

.footer__social {
    display: flex;
    gap: var(--spacing-4);
}

.footer__social-link {
    width: 40px;
    height: 40px;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.footer__social-link:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

/* Theme Toggle */
.theme-toggle {
    position: fixed;
    bottom: var(--spacing-6);
    right: var(--spacing-6);
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border: none;
    border-radius: 50%;
    color: white;
    font-size: var(--font-size-lg);
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-normal);
    z-index: 1000;
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-xl);
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal.active {
    opacity: 1;
    visibility: visible;
}

.modal__content {
    background-color: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.9);
    transition: transform var(--transition-normal);
}

.modal.active .modal__content {
    transform: scale(1);
}

.modal__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-6);
    border-bottom: 1px solid var(--border-color);
}

.modal__title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
}

.modal__close {
    background: none;
    border: none;
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    cursor: pointer;
    padding: var(--spacing-2);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.modal__close:hover {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.modal__form {
    padding: var(--spacing-6);
}

.modal__footer {
    text-align: center;
    margin-top: var(--spacing-6);
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

.modal__footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.modal__footer a:hover {
    color: var(--primary-dark);
}

/* Mobile Menu */
@media (max-width: 1023px) {
    .nav__menu {
        position: fixed;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--bg-primary);
        border-top: 1px solid var(--border-color);
        flex-direction: column;
        padding: var(--spacing-6);
        gap: var(--spacing-6);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-normal);
    }

    .nav__menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav__list {
        flex-direction: column;
        width: 100%;
        gap: var(--spacing-4);
    }

    .nav__link {
        display: block;
        padding: var(--spacing-3) 0;
        text-align: center;
        border-radius: var(--radius-lg);
        transition: background-color var(--transition-fast);
    }

    .nav__link:hover,
    .nav__link.active {
        background-color: var(--bg-secondary);
    }

    .nav__actions {
        flex-direction: column;
        width: 100%;
        gap: var(--spacing-3);
    }
    
    .nav__actions .theme-toggle {
        width: 35px;
        height: 35px;
        font-size: var(--font-size-sm);
    }

    .nav__toggle {
        display: block;
    }
}

/* Responsive Design */
@media (max-width: 640px) {
    .hero__title {
        font-size: var(--font-size-3xl);
    }

    .section__title {
        font-size: var(--font-size-2xl);
    }

    .feature__card {
        padding: var(--spacing-6);
    }

    .contact__item {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-3);
    }

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

/* Loading Animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

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

/* Success/Error Messages */
.message {
    padding: var(--spacing-4);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-4);
    font-weight: 500;
}

.message--success {
    background-color: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.message--error {
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

.dark-theme .message--success {
    background-color: #064e3b;
    color: #6ee7b7;
    border-color: #047857;
}

.dark-theme .message--error {
    background-color: #7f1d1d;
    color: #fca5a5;
    border-color: #dc2626;
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus Styles */
*:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .theme-toggle,
    .modal {
        display: none;
    }
    
    body {
        background: white !important;
        color: black !important;
    }
    
    .hero {
        padding-top: var(--spacing-8);
    }
}