:root {
    /* Color Variables */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #eaefff;
    --secondary: #f8f9fa;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;
    --dark: #343a40;
    --light: #f8fafc;
    --white: #ffffff;
    --text-dark: #343a40;
    --text-light: #6c757d;
    --border-color: #e1e5eb;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 10px 25px rgba(99, 102, 241, 0.15);
    --shadow-lg: 0 20px 50px rgba(99, 102, 241, 0.2);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Base Styles */
*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

body {
    background-color: #f5f8fe;
    color: var(--text-dark);
    min-height: 100vh;
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* Animated Background */
.animated-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
    background: linear-gradient(135deg, #f5f8fe 0%, #e9effd 100%);
}

.bg-pattern {
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(67, 97, 238, 0.03) 0%, transparent 20%),
        radial-gradient(circle at 90% 30%, rgba(67, 97, 238, 0.03) 0%, transparent 20%),
        radial-gradient(circle at 30% 70%, rgba(67, 97, 238, 0.03) 0%, transparent 20%),
        radial-gradient(circle at 80% 90%, rgba(67, 97, 238, 0.03) 0%, transparent 20%);
    animation: patternFloat 15s ease-in-out infinite alternate;
}

@keyframes patternFloat {
    0% {
        transform: translateY(-1%) translateX(-1%);
    }
    100% {
        transform: translateY(1%) translateX(1%);
    }
}

/* Floating Objects */
.floating-objects {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
}

.floating-object {
    position: absolute;
    opacity: 0.5;
    z-index: -1;
    transition: color var(--transition);
    animation: float 20s ease-in-out infinite;
}

.object-1 {
    top: 15%;
    left: 10%;
    font-size: 4rem;
    color: var(--primary);
    animation-delay: 0s;
}

.object-2 {
    top: 75%;
    left: 85%;
    font-size: 3rem;
    color: var(--success);
    animation-delay: 2s;
}

.object-3 {
    top: 25%;
    left: 90%;
    font-size: 3.5rem;
    color: var(--warning);
    animation-delay: 1s;
}

.object-4 {
    top: 80%;
    left: 15%;
    font-size: 3rem;
    color: var(--info);
    animation-delay: 3s;
}

.object-5 {
    top: 45%;
    left: 5%;
    font-size: 2.5rem;
    color: var(--danger);
    animation-delay: 2s;
}

.object-6 {
    top: 40%;
    left: 95%;
    font-size: 2.5rem;
    color: var(--primary);
    animation-delay: 0s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) translateX(0) rotate(0deg);
    }
    25% {
        transform: translateY(-25px) translateX(15px) rotate(5deg);
    }
    50% {
        transform: translateY(10px) translateX(-20px) rotate(-3deg);
    }
    75% {
        transform: translateY(-15px) translateX(25px) rotate(2deg);
    }
}

/* Header */
.header {
    padding: 2rem 0;
    text-align: center;
    animation: fadeDown 0.8s ease-out forwards;
}

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

.logo-wrapper {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
}

.logo-icon {
    width: 70px;
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--primary);
    border-radius: 0.5rem;
    color: white;
    font-size: 2.5rem;
    margin-right: 0.75rem;
    box-shadow: 0 5px 15px rgba(67, 97, 238, 0.3);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        transform: scale(1);
        box-shadow: 0 5px 15px rgba(67, 97, 238, 0.3);
    }
    50% {
        transform: scale(1.05);
        box-shadow: 0 5px 20px rgba(67, 97, 238, 0.4);
    }
    100% {
        transform: scale(1);
        box-shadow: 0 5px 15px rgba(67, 97, 238, 0.3);
    }
}

.logo-text {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.welcome-title {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.welcome-subtitle {
    font-size: 1.2rem;
    color: var(--text-light);
    max-width: 800px;
    margin: 0 auto 2rem;
    line-height: 1.5;
}

/* Main Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    flex: 1;
}

/* Role Selection Cards */
.role-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin: 1rem 0 3rem;
}

.role-card {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.95), rgba(255, 255, 255, 0.85));
    backdrop-filter: blur(20px);
    border-radius: 1.25rem;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    transition: var(--transition);
    position: relative;
    cursor: pointer;
    text-decoration: none;
    color: var(--text-dark);
    display: flex;
    flex-direction: column;
    height: 100%;
    animation: fadeIn 0.8s ease-out forwards;
    opacity: 0;
    border: 1px solid rgba(226, 232, 240, 0.8);
}

.role-card:nth-child(1) { animation-delay: 0.2s; }
.role-card:nth-child(2) { animation-delay: 0.4s; }
.role-card:nth-child(3) { animation-delay: 0.6s; }

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.role-card:hover {
    transform: translateY(-12px) scale(1.02);
    box-shadow: var(--shadow-lg);
}

.role-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    transform-origin: left;
    transform: scaleX(1);
    transition: transform 0.3s ease;
}

.role-card:hover::before {
    transform: scaleX(1);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.student-card::before { background: linear-gradient(90deg, #6366f1, #8b5cf6); }
.teacher-card::before { background: linear-gradient(90deg, #10b981, #059669); }
.admin-card::before { background: linear-gradient(90deg, #f59e0b, #d97706); }
.parent-card::before { background: linear-gradient(90deg, #ef4444, #dc2626); }

.role-header {
    padding: 2rem;
    text-align: center;
}

.role-icon {
    width: 90px;
    height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    border-radius: 50%;
    font-size: 2.5rem;
    transition: var(--transition);
}

.student-card .role-icon {
    background-color: rgba(67, 97, 238, 0.1);
    color: var(--primary);
}

.teacher-card .role-icon {
    background-color: rgba(46, 204, 113, 0.1);
    color: var(--success);
}

.admin-card .role-icon {
    background-color: rgba(243, 156, 18, 0.1);
    color: var(--warning);
}

.parent-card .role-icon {
    background-color: rgba(243, 156, 18, 0.1);
    color: var(--danger);
}
.role-card:hover .role-icon {
    transform: scale(1.1);
}

.student-card:hover .role-icon {
    background-color: var(--primary);
    color: var(--white);
    box-shadow: 0 5px 15px rgba(67, 97, 238, 0.3);
}

.teacher-card:hover .role-icon {
    background-color: var(--success);
    color: var(--white);
    box-shadow: 0 5px 15px rgba(46, 204, 113, 0.3);
}

.admin-card:hover .role-icon {
    background-color: var(--warning);
    color: var(--white);
    box-shadow: 0 5px 15px rgba(243, 156, 18, 0.3);
}
.parent-card:hover .role-icon {
    background-color: var(--danger);
    color: var(--white);
    box-shadow: 0 5px 15px rgba(243, 156, 18, 0.3);
}

.role-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.role-description {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.5;
}

.role-content {
    padding: 0 2rem 1.5rem;
    flex-grow: 1;
}

.role-features {
    list-style: none;
    margin-bottom: 1.5rem;
}

.role-feature {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 1rem;
    color: var(--text-light);
    font-size: 0.95rem;
}

.role-feature i {
    color: var(--primary);
    margin-top: 0.25rem;
    font-size: 0.85rem;
}

.teacher-card .role-feature i {
    color: var(--success);
}

.admin-card .role-feature i {
    color: var(--warning);
}

/* Action Button */
.role-action {
    background-color: var(--secondary);
    text-align: center;
    padding: 1.5rem;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
}

.role-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background-color: transparent;
    color: var(--text-dark);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.student-card .role-btn:hover {
    background-color: var(--primary);
    color: var(--white);
    border-color: var(--primary);
}

.teacher-card .role-btn:hover {
    background-color: var(--success);
    color: var(--white);
    border-color: var(--success);
}

.admin-card .role-btn:hover {
    background-color: var(--warning);
    color: var(--white);
    border-color: var(--warning);
}

.parent-card .role-btn:hover {
    background-color: var(--danger);
    color: var(--white);
    border-color: var(--danger);
}

/* Demo Notice */
.demo-notice {
    background-color: rgba(67, 97, 238, 0.05);
    border-left: 4px solid var(--primary);
    padding: 1.5rem;
    border-radius: 0.5rem;
    margin: 2rem 0;
    animation: fadeIn 0.8s ease-out forwards;
    animation-delay: 0.8s;
    opacity: 0;
}

.notice-title {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
    font-weight: 600;
    color: var(--primary);
}

.notice-text {
    color: var(--text-light);
    line-height: 1.5;
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem 0;
    color: var(--text-light);
    font-size: 0.9rem;
    animation: fadeUp 0.8s ease-out forwards;
    animation-delay: 1s;
    opacity: 0;
}

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

.footer-logo {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

/* Theme Toggle */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 100;
}

.theme-toggle-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    color: var(--text-dark);
    padding: 0.5rem;
    border-radius: 50%;
    background-color: var(--white);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    transition: all var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
}

.theme-toggle-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* Responsive */
@media (max-width: 992px) {
    .role-cards {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
        gap: 1.5rem;
    }
}

@media (max-width: 768px) {
    .welcome-title {
        font-size: 1.75rem;
    }

    .welcome-subtitle {
        font-size: 1.1rem;
    }

    .logo-icon {
        width: 60px;
        height: 60px;
        font-size: 2rem;
    }

    .logo-text {
        font-size: 2rem;
    }

    .role-cards {
        grid-template-columns: 1fr;
    }

    .floating-objects {
        display: none;
    }
}

/* Dark Mode */
body.dark-mode {
    background-color: #121212;
    color: #e1e1e1;
}

body.dark-mode .animated-bg {
    background: linear-gradient(135deg, #121212 0%, #1a1a1a 100%);
}

body.dark-mode .bg-pattern {
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(108, 140, 255, 0.05) 0%, transparent 20%),
        radial-gradient(circle at 90% 30%, rgba(108, 140, 255, 0.05) 0%, transparent 20%),
        radial-gradient(circle at 30% 70%, rgba(108, 140, 255, 0.05) 0%, transparent 20%),
        radial-gradient(circle at 80% 90%, rgba(108, 140, 255, 0.05) 0%, transparent 20%);
}

body.dark-mode .welcome-title,
body.dark-mode .role-title {
    color: #e1e1e1;
}

body.dark-mode .welcome-subtitle,
body.dark-mode .role-description,
body.dark-mode .role-feature,
body.dark-mode .notice-text,
body.dark-mode .footer {
    color: #a1a8af;
}

body.dark-mode .role-card {
    background-color: #1e1e1e;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

body.dark-mode .role-action {
    background-color: #252525;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

body.dark-mode .role-btn {
    color: #e1e1e1;
    border-color: #3a3a3a;
}

body.dark-mode .demo-notice {
    background-color: rgba(108, 140, 255, 0.1);
}

body.dark-mode .theme-toggle-btn {
    background-color: #1e1e1e;
    color: #e1e1e1;
}