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

body {
    font-family: 'Inter', sans-serif;
    background: #0a0c10;
    color: #ffffff;
    overflow-x: hidden;
    min-width: 1200px;
}

/* Background Effects */
.bg-wrapper {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
    overflow: hidden;
}

.gradient-bg {
    position: absolute;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 20% 30%, #0a0c10, #0f1119, #1a1f2e);
}

.gradient-bg::before {
    content: '';
    position: absolute;
    width: 150%;
    height: 150%;
    top: -25%;
    left: -25%;
    background: radial-gradient(circle, rgba(59,130,246,0.12) 0%, transparent 60%);
    animation: rotateSlow 25s linear infinite;
}

.gradient-bg::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: radial-gradient(circle at 25% 40%, rgba(139,92,246,0.06) 0%, transparent 30%),
                      radial-gradient(circle at 75% 60%, rgba(59,130,246,0.06) 0%, transparent 30%);
    animation: pulseBg 8s ease-in-out infinite;
}

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

@keyframes pulseBg {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; }
}

.particles {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
}

.particle {
    position: absolute;
    background: rgba(59,130,246,0.3);
    border-radius: 50%;
    pointer-events: none;
    animation: floatParticle 15s infinite linear;
}

@keyframes floatParticle {
    0% {
        transform: translateY(100vh) rotate(0deg);
        opacity: 0;
    }
    10% { opacity: 0.5; }
    90% { opacity: 0.5; }
    100% {
        transform: translateY(-20vh) rotate(360deg);
        opacity: 0;
    }
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInScale {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Container */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem 3rem;
    position: relative;
    z-index: 1;
}

/* Navigation */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    margin-bottom: 2rem;
    gap: 2rem;
    animation: fadeInUp 0.8s ease;
}

.logo {
    font-size: 1.6rem;
    font-weight: 700;
    background: linear-gradient(135deg, #ffffff, #3b82f6, #8b5cf6);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    white-space: nowrap;
}

.logo i {
    background: none;
    color: #3b82f6;
}

.nav-menu {
    display: flex;
    gap: 0.5rem;
    background: rgba(15, 20, 35, 0.6);
    backdrop-filter: blur(15px);
    padding: 0.5rem;
    border-radius: 3rem;
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.nav-btn {
    padding: 0.7rem 1.2rem;
    border: none;
    background: transparent;
    color: #9ca3af;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    border-radius: 2rem;
    transition: all 0.3s ease;
}

.nav-btn i {
    margin-right: 0.5rem;
}

.nav-btn:hover {
    color: white;
    background: rgba(59, 130, 246, 0.2);
    transform: translateY(-2px);
}

.nav-btn.active {
    background: linear-gradient(135deg, #3b82f6, #2563eb);
    color: white;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.3);
}

.nav-btn.login-btn {
    background: linear-gradient(135deg, #10b981, #059669);
    color: white;
}

.nav-btn.login-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: rgba(255, 255, 255, 0.1);
    padding: 0.5rem 1.2rem;
    border-radius: 2rem;
    backdrop-filter: blur(10px);
}

.user-info span {
    color: #60a5fa;
    font-weight: 600;
}

.logout-btn {
    background: rgba(239, 68, 68, 0.2);
    border: none;
    color: #f87171;
    padding: 0.4rem 1rem;
    border-radius: 2rem;
    cursor: pointer;
    transition: 0.3s;
}

.logout-btn:hover {
    background: rgba(239, 68, 68, 0.4);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(8px);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.modal.active {
    display: flex;
    animation: fadeInUp 0.3s ease;
}

.modal-content {
    background: linear-gradient(135deg, rgba(15, 20, 35, 0.95), rgba(10, 12, 16, 0.95));
    backdrop-filter: blur(15px);
    border-radius: 2rem;
    padding: 2rem;
    width: 100%;
    max-width: 450px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.modal-header h3 {
    font-size: 1.5rem;
}

.close-modal {
    background: none;
    border: none;
    color: #9ca3af;
    font-size: 1.5rem;
    cursor: pointer;
}

.close-modal:hover {
    color: white;
}

.auth-tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding-bottom: 0.5rem;
}

.auth-tab {
    background: none;
    border: none;
    color: #9ca3af;
    font-size: 1rem;
    font-weight: 600;
    padding: 0.5rem 1rem;
    cursor: pointer;
    border-radius: 2rem;
}

.auth-tab.active {
    background: linear-gradient(135deg, #3b82f6, #2563eb);
    color: white;
}

.auth-form {
    display: none;
}

.auth-form.active-form {
    display: block;
}

.form-group {
    margin-bottom: 1.2rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #9ca3af;
    font-size: 0.9rem;
}

.form-group input {
    width: 100%;
    padding: 0.8rem 1rem;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 1rem;
    color: white;
    font-size: 1rem;
}

.form-group input:focus {
    outline: none;
    border-color: #3b82f6;
}

.auth-btn {
    width: 100%;
    padding: 0.8rem;
    background: linear-gradient(135deg, #3b82f6, #2563eb);
    border: none;
    border-radius: 2rem;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: 0.3s;
}

.auth-btn:hover {
    transform: translateY(-2px);
}

.error-msg {
    color: #f87171;
    font-size: 0.8rem;
    margin-top: 0.5rem;
    text-align: center;
}

.success-msg {
    color: #4ade80;
    font-size: 0.8rem;
    margin-top: 0.5rem;
    text-align: center;
}

/* Pages */
.page {
    display: none;
    animation: fadeIn 0.5s ease;
}

.page.active-page {
    display: block;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #ffffff, #3b82f6, #8b5cf6);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 2rem 0 3rem;
    animation: fadeInUp 1s ease;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #ffffff, #60a5fa, #a78bfa);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.1rem;
    color: #9ca3af;
    max-width: 600px;
    margin: 0 auto;
}

/* Progress Section */
.progress-section {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.02));
    backdrop-filter: blur(15px);
    border-radius: 2rem;
    padding: 2.5rem;
    margin: 2rem 0;
    border: 1px solid rgba(255, 255, 255, 0.08);
    transition: all 0.3s;
    animation: fadeInScale 0.8s ease;
}

.progress-section:hover {
    border-color: rgba(59, 130, 246, 0.3);
    transform: translateY(-3px);
}

.progress-header {
    text-align: center;
    margin-bottom: 2rem;
}

.progress-header h2 {
    font-size: 1.6rem;
    font-weight: 600;
}

.progress-header h2 i {
    color: #3b82f6;
    margin-right: 0.5rem;
}

.progress-header p {
    color: #6b7280;
    font-size: 0.9rem;
}

.progress-main {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4rem;
    flex-wrap: nowrap;
}

.progress-stats {
    text-align: center;
}

.stats-number {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, #6b7280, #9ca3af);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    line-height: 1;
}

.stats-label {
    font-size: 0.9rem;
    color: #6b7280;
    margin-top: 0.3rem;
}

.stats-divider {
    width: 40px;
    height: 2px;
    background: rgba(107, 114, 128, 0.3);
    margin: 0.8rem auto;
}

.linear-progress {
    width: 260px;
    margin: 0 auto;
}

.progress-bar-container {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 1rem;
    height: 10px;
    overflow: hidden;
}

.progress-fill {
    width: 0%;
    height: 100%;
    background: linear-gradient(90deg, #6b7280, #9ca3af);
    border-radius: 1rem;
    transition: width 0.5s ease;
}

.circle-wrapper {
    position: relative;
    width: 150px;
    height: 150px;
}

.circle-svg {
    transform: rotate(-90deg);
}

.circle-bg {
    stroke: rgba(255, 255, 255, 0.1);
    stroke-width: 7;
    fill: none;
}

.circle-progress {
    stroke: url(#gradientGray);
    stroke-width: 7;
    fill: none;
    stroke-linecap: round;
    stroke-dasharray: 440;
    stroke-dashoffset: 440;
    transition: stroke-dashoffset 0.5s ease;
}

.circle-percentage {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

.circle-percentage .percent {
    font-size: 1.6rem;
    font-weight: 800;
    color: #9ca3af;
}

.circle-percentage .label {
    font-size: 0.65rem;
    color: #6b7280;
}

/* Section Titles */
.section-title {
    text-align: center;
    font-size: 2rem;
    margin: 3rem 0 2rem;
    font-weight: 700;
}

.section-title i {
    margin-right: 0.8rem;
    color: #3b82f6;
}

/* Skills Grid */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    margin: 2rem 0;
}

.skill-card {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.05), rgba(255, 255, 255, 0.02));
    backdrop-filter: blur(12px);
    border-radius: 1.5rem;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.08);
    transition: all 0.4s ease;
    cursor: pointer;
    animation: fadeInUp 0.8s ease backwards;
}

.skill-card:hover {
    transform: translateY(-8px);
    border-color: rgba(59, 130, 246, 0.5);
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(139, 92, 246, 0.05));
    box-shadow: 0 20px 35px rgba(0, 0, 0, 0.3);
}

.card-icon {
    font-size: 2.8rem;
    margin-bottom: 1rem;
    display: inline-block;
}

.skill-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.8rem;
}

.skill-card p {
    color: #9ca3af;
    line-height: 1.5;
    font-size: 0.95rem;
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    margin-top: 1rem;
}

.tech-tag {
    background: rgba(59, 130, 246, 0.12);
    padding: 0.2rem 0.7rem;
    border-radius: 2rem;
    font-size: 0.65rem;
    color: #60a5fa;
}

/* Steps Container */
.steps-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin: 3rem 0;
}

.step-card {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(12px);
    border-radius: 1.5rem;
    padding: 1.8rem;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.08);
    transition: all 0.3s;
    animation: fadeInUp 0.8s ease backwards;
}

.step-card:hover {
    transform: translateY(-4px);
    border-color: rgba(59, 130, 246, 0.4);
    background: rgba(59, 130, 246, 0.05);
}

.step-number {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    font-size: 1.3rem;
    font-weight: bold;
}

.step-card h4 {
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.step-card p {
    color: #9ca3af;
    font-size: 0.85rem;
}

/* Lesson Items */
.lekcija-item {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 16px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: all 0.3s ease;
}

.lekcija-item.completed {
    border-left: 5px solid #10b981;
    opacity: 0.85;
}

.lekcija-item:hover {
    transform: translateX(5px);
}

.btn-complete {
    background: #10b981;
    color: white;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 30px;
    cursor: pointer;
    margin-top: 0.5rem;
    font-weight: bold;
    transition: all 0.3s ease;
}

.btn-complete:hover {
    transform: scale(1.02);
}

.btn-complete.completed-btn {
    background: #2c3e66;
    cursor: default;
    opacity: 0.7;
}

.btn-complete.disabled-btn {
    background: #94a3b8;
    cursor: not-allowed;
    opacity: 0.5;
}

.btn-complete.disabled-btn:hover {
    transform: none;
}

/* Live Demo Container */
.live-demo-container {
    background: linear-gradient(135deg, #1e1e2f, #2d2d3d);
    border-radius: 16px;
    margin-top: 1rem;
    overflow: hidden;
}

.demo-header {
    background: #16213e;
    padding: 0.8rem 1rem;
    display: flex;
    gap: 1rem;
    border-bottom: 1px solid #0f3460;
}

.demo-btn {
    background: #6366f1;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: all 0.2s;
}

.demo-btn:hover {
    background: #4f46e5;
    transform: translateY(-2px);
}

.demo-copy-btn {
    background: #f59e0b;
}

.demo-copy-btn:hover {
    background: #d97706;
}

.demo-output {
    background: #0f0f1a;
    padding: 1rem;
    font-family: monospace;
    font-size: 14px;
    color: #e0e0e0;
    min-height: 80px;
    border-top: 1px solid #0f3460;
    white-space: pre-wrap;
}

.demo-output.error {
    color: #ef4444;
}

.demo-output.success {
    color: #10b981;
}

.python-output {
    background: #0f0f1a;
    padding: 1rem;
    font-family: monospace;
    font-size: 14px;
    color: #e0e0e0;
    min-height: 80px;
    border-top: 1px solid #0f3460;
    white-space: pre-wrap;
}

.python-output.success {
    color: #10b981;
}

.python-output.error {
    color: #ef4444;
}

/* Live Editor */
.live-editor-wrapper {
    background: #1a1a2e;
    border-radius: 20px;
    overflow: hidden;
    margin-top: 1rem;
    border: 1px solid rgba(99, 102, 241, 0.3);
}

.top-bar {
    background: #16213e;
    padding: 1rem 1.8rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #0f3460;
    gap: 1rem;
}

.title {
    color: white;
    font-size: 1.3rem;
    font-weight: 600;
}

.title span {
    color: #6366f1;
}

.file-status {
    color: #f59e0b;
    font-size: 0.85rem;
    background: rgba(245, 158, 11, 0.15);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
}

.live-editor-container {
    display: flex;
    flex-direction: column;
    min-height: 600px;
}

.editor-row {
    display: flex;
    flex: 2;
    min-height: 450px;
}

.editor-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: #1a1a2e;
    border-right: 1px solid #0f3460;
}

.editor-section:last-child {
    border-right: none;
}

.editor-header {
    background: #16213e;
    padding: 0.7rem 1rem;
    border-bottom: 1px solid #0f3460;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.editor-header h3 {
    font-size: 1rem;
    font-weight: 600;
}

.editor-header h3 i {
    margin-right: 0.5rem;
}

.export-btn-small {
    background: #10b981;
    padding: 0.3rem 0.8rem;
    border-radius: 1rem;
    border: none;
    color: white;
    cursor: pointer;
    font-size: 0.7rem;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}

.code-area {
    flex: 1;
    padding: 0.5rem;
}

.code-area textarea {
    width: 100%;
    height: 100%;
    background: #0f0f1a;
    color: #e0e0e0;
    border: 1px solid #0f3460;
    border-radius: 12px;
    padding: 1rem;
    font-family: monospace;
    font-size: 13px;
    line-height: 1.5;
    resize: none;
    outline: none;
}

.code-area textarea:focus {
    border-color: #6366f1;
}

.export-row {
    background: #16213e;
    padding: 1rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    border-top: 1px solid #0f3460;
    border-bottom: 1px solid #0f3460;
}

.export-btn {
    background: linear-gradient(135deg, #10b981, #059669);
    color: white;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 2rem;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.export-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.4);
}

.export-all-btn {
    background: linear-gradient(135deg, #8b5cf6, #6366f1);
}

.preview-section {
    background: #ffffff;
    border-top: 1px solid #0f3460;
}

.preview-header {
    background: #16213e;
    padding: 0.7rem 1.2rem;
    color: white;
    font-size: 0.9rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.preview-frame {
    width: 100%;
    height: 350px;
    border: none;
    background: white;
}

.editor-footer {
    background: #16213e;
    padding: 0.8rem 1rem;
    display: flex;
    gap: 1rem;
    border-top: 1px solid #0f3460;
}

.action-btn {
    background: #0f3460;
    color: white;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.action-btn:hover {
    transform: translateY(-2px);
}

.reset-btn {
    background: #ef4444;
}

.run-btn {
    background: #6366f1;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: #10b981;
    color: white;
    padding: 0.8rem 1.5rem;
    border-radius: 12px;
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
    z-index: 1000;
}

.toast.show {
    opacity: 1;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem 0 1.5rem;
    margin-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    color: #6b7280;
    font-size: 0.85rem;
}

footer i {
    color: #3b82f6;
    margin: 0 0.2rem;
}

/* Responsive */
@media (max-width: 1200px) {
    .container {
        padding: 1.5rem;
    }
    
    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .steps-container {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    body {
        min-width: auto;
    }
    
    .navbar {
        flex-direction: column;
    }
    
    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
    
    .steps-container {
        grid-template-columns: 1fr;
    }
    
    .progress-main {
        flex-direction: column;
        gap: 2rem;
    }
    
    .editor-row {
        flex-direction: column;
    }
}