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

body {
    font-family: 'Segoe UI', system-ui, sans-serif;
    background: #0a1628;
    color: #e0e8f0;
    min-height: 100vh;
}

header {
    text-align: center;
    padding: 3rem 1rem 1.5rem;
    background: linear-gradient(180deg, #0f2035 0%, #0a1628 100%);
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(90deg, #f59e0b, #ef4444);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    color: #8899aa;
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.5;
}

/* Slider */
.slider-section {
    text-align: center;
    padding: 2rem 1rem;
    position: sticky;
    top: 0;
    background: rgba(10, 22, 40, 0.95);
    backdrop-filter: blur(10px);
    z-index: 10;
    border-bottom: 1px solid rgba(255,255,255,0.05);
}

.temp-display {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 0.25rem;
    transition: color 0.4s;
}

.temp-label {
    font-size: 0.95rem;
    color: #8899aa;
    margin-bottom: 1.25rem;
}

.slider-container {
    max-width: 500px;
    margin: 0 auto;
    position: relative;
}

input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 8px;
    border-radius: 4px;
    outline: none;
    cursor: pointer;
    transition: background 0.3s;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.4);
    cursor: grab;
}

input[type="range"]::-moz-range-thumb {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.4);
    cursor: grab;
    border: none;
}

.slider-labels {
    display: flex;
    justify-content: space-between;
    margin-top: 0.5rem;
    font-size: 0.8rem;
    color: #667788;
}

/* Timeline */
.timeline {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1rem 4rem;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, #f59e0b, #ef4444, #7f1d1d);
    transform: translateX(-50%);
}

.milestone {
    position: relative;
    margin-bottom: 3rem;
    opacity: 0.25;
    transform: translateY(10px);
    transition: opacity 0.5s, transform 0.5s;
}

.milestone.active {
    opacity: 1;
    transform: translateY(0);
}

.milestone-dot {
    position: absolute;
    left: 50%;
    top: 1.5rem;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    transform: translateX(-50%);
    z-index: 2;
    border: 3px solid #0a1628;
    transition: background 0.4s, box-shadow 0.4s;
}

.milestone.active .milestone-dot {
    box-shadow: 0 0 16px rgba(245, 158, 11, 0.5);
}

.milestone-content {
    width: 44%;
    padding: 1.25rem 1.5rem;
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,0.06);
    transition: background 0.4s, border-color 0.4s;
}

.milestone:nth-child(odd) .milestone-content {
    margin-left: 56%;
}

.milestone:nth-child(even) .milestone-content {
    margin-right: 56%;
    text-align: right;
}

.milestone-temp {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 0.4rem;
}

.milestone-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.milestone-desc {
    font-size: 0.9rem;
    line-height: 1.6;
    color: #aabbcc;
}

.milestone-icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

/* Impact bars */
.impact-section {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 1rem 4rem;
}

.impact-section h2 {
    text-align: center;
    font-size: 1.5rem;
    margin-bottom: 2rem;
    color: #ccdde8;
}

.impact-bar-group {
    margin-bottom: 1.5rem;
}

.impact-bar-label {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.4rem;
    font-size: 0.9rem;
}

.impact-bar-track {
    height: 12px;
    background: rgba(255,255,255,0.06);
    border-radius: 6px;
    overflow: hidden;
}

.impact-bar-fill {
    height: 100%;
    border-radius: 6px;
    transition: width 0.6s ease, background 0.4s;
    width: 0%;
}

/* Responsive */
@media (max-width: 640px) {
    header h1 { font-size: 1.4rem; }
    .temp-display { font-size: 3rem; }

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

    .milestone-dot {
        left: 20px;
    }

    .milestone-content {
        width: calc(100% - 50px) !important;
        margin-left: 50px !important;
        margin-right: 0 !important;
        text-align: left !important;
    }
}