/* ===============
   Tokens
================ */
:root {
    --ink-900: #1f1f1f;
    --ink-700: #2b3147;
    --ink-500: #5f6b7a;

    --brand-700: #0e475f;
    --brand-600: #165c7d;
    --brand-500: #23759c;
    --brand-400: #398fba;

    --card-radius: 18px;
    --soft-shadow: 0 18px 40px rgba(0, 0, 0, 0.12);
    --rail-max: 980px;
    --rail-pad: clamp(16px, 5vw, 5%);

    /* animation controls */
    --draw-speed: 7s; /* perimeter loop time */
    --draw-thickness: 2px; /* animated line thickness */
    --base-border: #d9e6ee; /* static border color */
}

/* ===============
   Shell
================ */
.problem-wrap {
    display: flex;
    justify-content: center;
    padding: clamp(44px, 7vw, 88px) var(--rail-pad);
    background: #e7f0f4;
}

.problem-card {
    position: relative;
    background: #fff;
    border-radius: var(--card-radius);
    padding: clamp(28px, 4vw, 48px);
    max-width: var(--rail-max);
    width: 100%;
    box-shadow: var(--soft-shadow);
    overflow: hidden;

    /* static border always visible */
    border: 1px solid var(--base-border);
    background-clip: padding-box;
}

/* ===============
   Sequential border animation
   Top -> Right -> Bottom -> Left -> loop
================ */
.problem-card::before {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: var(--card-radius);
    pointer-events: none;

    /* start with only the top edge visible */
    border: var(--draw-thickness) solid transparent;
    border-top-color: var(--brand-500);

    animation: draw-border var(--draw-speed) linear infinite;
}

@keyframes draw-border {
    0% {
        border-top-color: var(--brand-500);
        border-right-color: transparent;
        border-bottom-color: transparent;
        border-left-color: transparent;
    }
    24.99% {
        border-top-color: var(--brand-500);
        border-right-color: transparent;
        border-bottom-color: transparent;
        border-left-color: transparent;
    }
    25% {
        border-top-color: var(--brand-500);
        border-right-color: var(--brand-500);
        border-bottom-color: transparent;
        border-left-color: transparent;
    }
    49.99% {
        border-top-color: var(--brand-500);
        border-right-color: var(--brand-500);
        border-bottom-color: transparent;
        border-left-color: transparent;
    }
    50% {
        border-top-color: var(--brand-500);
        border-right-color: var(--brand-500);
        border-bottom-color: var(--brand-500);
        border-left-color: transparent;
    }
    74.99% {
        border-top-color: var(--brand-500);
        border-right-color: var(--brand-500);
        border-bottom-color: var(--brand-500);
        border-left-color: transparent;
    }
    75% {
        border-top-color: var(--brand-500);
        border-right-color: var(--brand-500);
        border-bottom-color: var(--brand-500);
        border-left-color: var(--brand-500);
    }
    100% {
        border-top-color: var(--brand-500);
        border-right-color: transparent;
        border-bottom-color: transparent;
        border-left-color: transparent;
    }
}

/* body sits above the animated layer */
.problem-body {
    position: relative;
}

/* ===============
   Header
================ */
.problem-head {
    margin: 0 0 clamp(16px, 2.4vw, 24px);
}
.problem-title {
    margin: 0 0 6px;
    font-size: clamp(22px, 3.2vw, 32px);
    line-height: 1.2;
    color: var(--ink-900);
}
.problem-kicker {
    margin: 0;
    font-size: clamp(14px, 2vw, 18px);
    font-weight: 500;
    color: var(--ink-700);
}

/* ===============
   Single column layout
================ */
.problem-body.problem-single {
    display: block;
}

/* ===============
   Rows and icons
================ */
.p-stack {
    display: flex;
    flex-direction: column;
    gap: clamp(14px, 2.6vw, 20px);
}

.p-row {
    display: grid;
    grid-template-columns: 92px 1fr;
    gap: 16px;
    align-items: start;
    background: #f7fbfe;
    border: 1px solid #e1edf3;
    border-radius: 16px;
    padding: 16px;
    transition: transform 0.18s ease, box-shadow 0.18s ease,
        border-color 0.18s ease;
}
.p-row:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 24px rgba(0, 0, 0, 0.08);
    border-color: #d0e6f0;
}

.p-icon {
    position: relative;
    display: grid;
    place-items: center;
    width: 92px;
    height: 92px;
    border-radius: 18px;
    background: radial-gradient(
        ellipse at 30% 30%,
        #ffffff 0%,
        #f2f9fd 60%,
        #e9f3fa 100%
    );
    border: 1px solid #d9e9f3;
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}
.p-icon .p-svg {
    width: 52px;
    height: 52px;
}

/* keep glow off for clean look */
.p-glow {
    display: none;
}

.p-text {
    min-width: 0;
}
.problem-copy {
    color: var(--ink-700);
    line-height: 1.65;
    font-size: 16px;
    margin: 0;
}

/* ===============
   Interview quote area
================ */
.p-quote {
    position: relative;
    margin: 16px 0 0;
    padding-bottom: 16px;
    border-bottom: 3px solid var(--ink-900); /* bold underline */
}

.problem-quote {
    font-style: italic;
    font-size: 15px;
    color: var(--ink-900);
    margin: 0;
}
.problem-cite {
    display: block;
    margin-top: 6px;
    font-size: 13px;
    color: var(--ink-500);
}

/* ===============
   Responsive tweaks
================ */
@media (max-width: 560px) {
    .p-row {
        grid-template-columns: 76px 1fr;
        padding: 14px;
    }
    .p-icon {
        width: 76px;
        height: 76px;
        border-radius: 16px;
    }
    .p-icon .p-svg {
        width: 44px;
        height: 44px;
    }
}

/* ===============
   Motion guardrails
================ */
@media (prefers-reduced-motion: reduce) {
    .problem-card::before {
        animation: none !important;
    }
}